Gastroenterology Flashcards

Question

Chronic liver failure

Answer 1

symptoms: scleral icterus, palmar erythema, clubbing, wasting, portal HTN, cholestasis, hypotonia management: - liver transplant: 86% long term survival - medications: immunosuppression, antibacterial, antifungal, antiviral, antiHTN, supplements, bile drainage

Answer 2

30-40% risk DM May not have raised enzymes Causes: obstructive, genetic (cationic trypsinogen gene defect SPINK1)

Answer 3

Gram positive rod Toxin A (enterotoxin): act on intestinal mucosa Toxin B (cytotoxin): increases vasc permeability - both cause cell death Increased infection 2nd/3rd generation cephalosporin Diagnosis C-difficile or toxin in stool Culture doesn't differentiate toxin producing from non toxin producing Sigmoidoscopy: nodules/plaques Treatment vancomycin or metronidazole

Answer 4

1:100 F:M, 2:1. Caucasians mainly. Usually presents 10-40yr High risk groups: **10% 1st degree relative risk, T21** (16% affected), T1DM (2-5%), IgA deficiency (10%), Turner’s, William’s, Autoimmune thyroiditis (2-5%) Genetics:: MHC short arm ch6 – gene cluster of HLA class II. HLA-DQ2 and/or DQ8 found in 99% of ppl w coeliac (40% in the general population) Pathophysiology: gluten to gliadin, enters cell via injury, deaminated gliadin picked up HLA FQ2 + DQ8, T cell activation, B cell activation, inflammatory cascade, produce antigliadin/endomysium/tTG Biopsy: villous atrophy Tx: gluten free diet, resolution of symptoms weeks to months

Answer 5

tubular or spherical structures firmly attached to intestine with common blood supply associations: anomalies of urinary/genital anomaly presentation: volvulus, intussusception at lead point symptoms: abdominal pain, mass, GI bleeding

Answer 6

**genetic:** AR mutation SLC26A3 **cause:** defective chloride/bicarb transport mechanism distal ileum/colon **clinical:** severe watery diarrhoea at birth **investigations:** hypokalaemia, hypochloremia, _alkalosis_, stool Cl\>Na **management:** IVF

Answer 7

Immune mediated igE or non IgE response Most common allergy in young child (2% \<4yrs) 3rd most common cause of anaphylaxis Onset days- weeks after introduction cow's milk IgE mediated: mild anaphylaxis minutes to 2 hrs Mixed IgE/nonIgE: atopic eczema, allergic eosinophilic gastroenteritis NonIgE: delayed \>2hrs GI allergy is NonIgE Most develop tolerance Diagnosis: Food challenge or Cow's mild specific IgE RAST Treatment: soy formula (10-20% soy allergy also), extensively hydrolysed, AA formula

Answer 8

**Type 1: AR severe** - absent UGT - jaundice d2-3 - phototherapy for life **Type 2: AD milder** - UGT levels low but detectable - responds to phenobarbitone - late onset childhood/adulthood

Answer 9

7/100,000 peak 8-14yrs M:F 1:1 Relapsing remitting Site: any part GIT - favors terminal ileum * 35% involves ileum alone * 45% involves ileum and colon * 20% involves colon alone (preference for right side) * - Colonic involvement right-sided* * - Rectosigmoid often spared* * - Upper GIT more commonly involved in kids \>adults* - skip lesions Histology: - transmural, non caseating granulomas, goblet cells present, islands normal tissue Smoking: - twice as common in smokers Symptoms: malaise, fever, anorexia, nausea, vomiting, weight loss, bleeding rate exept with colitis Examination: RIF mass, fever, clubbing, abdo tenderness, anorectal disease, perianal disease (25%), oro-facial granulmoatosis, apthous ulcers Diagnosis: - pANCA (20%) – if +ve, more likely to have UC like distribution - ASCA (40-80%): ASCA assoc with more severe disease, fistulising disease - Anti-OmpC : potential marker of IBD (50%) - CBir1 – other antimicrobial antibody Treatment: steroids, 5-ASA, thiopurines (azathiopurines, 6-MP), infliximab

Answer 10

**definition:** parasitic protozoan cryptosporidium **source:** transmitted as microbial cysts via faecal-oral route **timing:** may be acute or chronic - symptoms 5-10 days after infection and last up to 2 weeks **clinical:** - significant watery diarrhoea, fever, abdominal pain, jaundice, reactive arthritis - can spread to biliary tract causing cholestasis **pathogenesis: (adherence/inflammation)** - parasite attaches duodenal brush border damaging it - malabsorption and osmotic diarrhoea - enveloped membrane and become intracellular - excreted as oocytes **detection:** microscopy, staining, Ab detection

Answer 11

* Implicated as cause of persistent diarrhoea in developing world * Transmission through infected animals; person-person; contaminated water * Incubation 2-14 days * Assocated with ***profuse, watery, nonbloody diarrhoea +/- vomiting, abdo pain, nausea, anorexia, myalgia, weakness, headache, fever*** * Malabsorption, weight loss, malnutrition in severe cases * Usually self limiting in immunocompetent patients, although diarrhoea may persist for several weeks (oocyst shedding may persist many weeks after symptoms resolve) * Rx: nitazoxanide

Answer 12

* = at least 5 attacks, or a minimum of 3 attacks in 6 months * Severe episodes, well between, each episode similar * Early morning * Positive FHx of cyclical vomiting OR migraine * _Chronic sinusitis_ – only infective correlation * _Metabolic_ * Consider malrotation * Rx: anti-migraine

Answer 13

**clinical:** early abdo/bowel distension, vomiting, rectal mucus plugging **complications:** meconium ileus (15%), 50% associated volvulus, jejunoileal atresia, bowel perforation, meconium peritonitis **AXR:** distended/thickened loops of intestine - meconium with swallowed air: ground glass sign

Answer 14

Most common skin condition associated coeliac disease Extensor surfaces and trunk Itchy

Answer 15

Biopsy to confirm anyone with positive serology or high risk CD

Answer 16

**incidence**: AR, rare except in sephardic jews **genetics:** ABCC2 gene **pathophysiology:** increased conjugate bilirubin due to impaired excretion of bilirubin glucuronidase **clinical:** mild conjugated hyperbilirubinaemia

Answer 17

epidemiology: 1/10,000, 50% prems, 50% chromosomal abnormalities (33% T21) cause: failired re-canalisation of duodenal lumen due to persistence of replicating epithelial cells pathophysiology: thin membrane occluding lumen, fibrous cord between, gap between 2 segments, web associated: CHD (30%), malrotations (20%), annular pancreas (30%), renal (15%), TOF (10%) clinical: bilious vomiting w/o distension 1st day life, hx polyhydramnios AXR: double bubble treatment: drip and tuck, surgical correction prognosis: 90% survival

Answer 18

**definition:** gram negative rod **source:** food (raw beef), milk **timing:** onset 1-8 days lasting 5-10 days **clinical:** severe bloody diarrhoea, pain, vomiting - sometime renal failure causing HUS (10%) (\<5yrs) in which RBCs destroyed causing anaemia/thrombocytopaenia and kidney failure **pathogenesis:** - strains of ecoli with shigella like toxin - A/B subunits allow attachment/uptake/apoptosis **diagnosis:** Ecoli O157:H7 requires special media to grow

Answer 19

**protein:** 4kcal/g (15% intake) **carbohydrate:** 4kcal/g (50% intake) **fat:** 10kcal/g (30-50% intake)

Answer 20

Colonises and adheres to enterocytes small bowel via surface pili Hypersecretion of fluids/electrolytes 2 toxins: heat labile enterotoxin (LT) or heat stable enterotoxin (similiar structure to cholera toxin)

Answer 21

- leading cause of bacterial diarrhoea developed countries **source:** water/food contaminated faeces **timing:** incubation 1-3 days, duration 3-7 days **clinical:** watery diarrhoea, cramps, vomiting, fever **pathogenesis:** - enterotoxins LT/ST presence produces more severe diarrhoea - B subunit attaches/A enters causing secretion Cl/H2O **diagnosis:** stool culture

Answer 22

Mixed IgE/nonIgE food protein allergy Boys\>girls, caucasian Causes: genetic, environment, Tcell Clinical, dysphagia, abdo pain, vomiting, food impaction, GORD, diarrhoea Associated atopy Diagnosis: biopsy (mucosal inflammation, eosinophilic infiltrates/microabscesses/furrowing) Treatment: elimination diet (milk most common trigger), steroids, topical

Answer 23

eg neocate, MCT peptide * Amino acids, coconut/vegetable oils (combo of MCT\>LCT), carb = glucose * Very high osmolarity * Indications: SBS, pancreatitis, severe multiple food protein allergy

Answer 24

1:10,000 inflammation of the bile ducts leading to progressive obliteration of extrahepatic biliary tract Symptoms: jaundice, hepatosplenomegally, acholic stool US: absence of gall bladder Assessment: hepatobiliary scintigraphy Treatment: Kansai procedure

Answer 25

**genetics:** AD variant tumour suppressor gene APC (adenomatous polyposis coli) **incidence:** 1/10,000 **clinical:** multiple colorectal adenomatous polyps (\>100) - GI bleeding, abdominal pain, diarrhoea **diagnosis:** suspected if \>10 colorectal adenomas and then genetic testing

Answer 26

**dietary fat**: triglycerides (3 fatty acid molecules + glycerol backbone) **digestion:** - lipase in stomach emulsifies lipid droplets - pancreatic lipase/colipase/esterase/phospholipase hydrolyse TG in duodenum to 2 FA + monoglycerides - products of lipolysis are insoluble (require bile salts) - bile salts (micelles) solubilise FA by incorporating them into their structure **absorption:** - in cell monoglycerides + FA re-esterified to TG (in phospholipid/cholesterol/protein to form chylomicrons) which go into the lymphatics - MC TG are water soluble don’t need micelles; they are unchanged FFA in the portal venous system

Answer 27

**source:** liver, kidney, yeast, green vegetables, nuts **amount:** 50microg/day, lasts 3-4 months **absorption:** duodenum/jejunum **decreased absorption:** methotrexate, trimethoprim, OCP, phenytoin, phenobarbiton **cells:** enters cell via specific receptor **-** folic acid to dihydrofolate reductase to tetrahydrofolate FH4 **causes of deficiency:** - congenital folate malabsorption (AR, onset 3 months) - congenital DHF reductase deficiency (onset infancy) **clinical:** anaemia, glossitis, jaundice, bleeding, infections, NO NEURO SX **diagnosis:** macrocytic anaemia, normal B12, low folate/methylmalonic acid, increased homocysteine

Answer 28

**incidence:** rare AR **definition:** IEM with absence enzyme aldolase B **clinical:** vomiting, hypoglycemia, jaundice, hemorrhage, hepatomegaly, hyperuricemia and potentially kidney failure after introduction of fruit into diet **diagnosis:** DNA screening, fructose challenge **treatment:** avoid fructose

Answer 29

Biliary tree and hepatocytes Raised in obstruction (with ALP) Inducible enzyme

Answer 30

INCREASE gastric acid secretion: * Histamine (via H2 receptors)→↑cAMP * Acetylcholine (via M3 muscarinic receptors)→ ↑ intracellular free Ca2+ * Gastrin (via enterochromaffin-like cells)→ ↑ histamine release DECREASE acid secretion: * PGE2 (decreased intracellular Ca+) * ? sympathetic drive, intestinal peptides eg. CCK, secretin

Answer 31

aka Menetrier's disease **definition:** hyperplasia of gastric pits and superficial epithelium causing large mucosal folds of stomach (Replacement normal gastric glands and parietal cells by hyperplastic mucus secreting cells) **pathophysiology:** - increased permeability results in hypochlorhydria/protein loss **clinical:** epigastric pain, vomiting, upper GI bleeding **causes:** childhood form associated CMV

Answer 32

Released by G cells in stomach, duodenum, pancreas Stimulates secretion HCl by parietal cells of the stomach/aids in gastric motility

Answer 33

GERD is physiological 40% infants vomit once per day Resolution 50% by 6m, 75% 1yr, 95% 18m Gastric acidity increased in first 4 months Cause: transient LES relaxations Anatomical issues: hiatus hernia, defective crural/diaphragmatic musculature, intermittent intestinal obstruction Functional: achalasia, increased intrabdominal pressure, theophylline

Answer 34

* Foregut = from pharynx to upper ½ of duodenum (including liver, gallbladder and pancreas) * Midgut = distal ½ of duodenum to proximal 2/3 of transverse colon * Hindgut = distal 1/3 of transverse colon to rectum

Answer 35

**Definition:** protozoan parasite **Incidence:** most common intestinal paracyte **Tranismission:** - faecal oral transmission via water/food disease **Pathophysiology:** - ingest cysts (10-100), each ingested cyst then makes 2 trophozoites - trophozoites colonize the lumen of the duodenum, and proximal jejunum, where they attach to brush border and multiply in a binary fission - cause villous atrophy **Incubation:** 1-2 weeks **Clinical:** - diarrhoea, malaise, foul smelling/fatty stool, abdominal pain. bloating, vomiting, fever - NO blood/mucous/WCC in stool - symptoms last up to 2 weeks and may become chronic - varying degrees of malabsorption occur – sugars, fats and fat soluble vitamins - may become chronic in 50% of patients waxing/waning for months **Diagnosis:** - stool microscopy (90% diagnosed 3 stool specimens)

Answer 36

2-5% (30% carriers) autosomal recessive decrease UDPGT activity (30-40%) asymptomatic unconjugated SBR in illness/stress/fasting normalises with phenobarbitone increases with nicotinic acid decreased clearance free FA

Answer 37

autosomal recessive cause: deficiency bilirubin UGT (uridine diphosphate glucuronosyl transferase) Investigations: normal LFTs/liver histology Types: type 1- AR, high risk kernicterus, lifelong phototherapy/liver transplant type 2-AD, may require PT, phenobarbitone activates some enzymes

Answer 38

chromosome 2 repeat in TATA box incidence: 7% M\>F cause: mild bilirubin UGT deficiency symptoms: jaundice tx: no treatment, normal lifespan

Answer 39

**incidence:** 1/500,000 **definition:** AR mutation sodium/glucose co-transporter (SGLT-1) **clinical:** early osmotic diarrhea, dehydration, acidosis **diagnosis:** - reducing substances in stools - glycosuria despite hypoglycaemia - breath H₂ positive **treatment:** fructose based diet

Answer 40

transient lower oesophageal sphincter relaxation physiology: full stomach, LES relaxation, secondary peristalsis of oeso neonates: 40-50x per day, resolves by 12months, uncomplicated in 60% complications: reflux apnoea, reflex bronschospasm, pain, bleeding, Barret's associated: poor weight gain management: conservatively, trial cow's milk elimination (3 days), breast feed, thicken feeds, drugs not 1st line, fundoplasty

Answer 41

**drugs:** ranitidine, cimetidine **pharmacology:** decrease parietal HCl secretion **use:** GORD, PUD, gastritis

Answer 42

**virus:** hepadnavirus **prevalence**: \<1% **pathogenesis:** lifelong non curable immune mediated cell injury **risk factors:** - age: younger higher risk chronic hep ?(neonate 95%, early child 25%, later child 10%) - perinatal exposure to HBsAg +ve mother (highest HBeAg positive (80% infected) negative (10%)) - breast feeding DOES NOT increase risk - IVDU - sex - blood transfusion: HBV 1:150,000 - needstick: HBV 33% **clinical:** - acute HBV: 6-7wks post exposure: ALT, lethargy, anorexia, malaise, 8-9wks jaundice for 4 weeks - chronic HBV (10% of acute): HBsAg \>6m, cirrhosis, HCC **treatment:** only if abnormal LFTs - IFNa2b: 25% eradication rate

Answer 43

Perform HBsAg, Anti-HBs, Anti-HBc - HBsAg first to rise in infection but falls rapidly - Anti-HBc IgM rises realy and remains mths-years - Anti-HBs marks recovery and protection - Vacinated Anti-HBs Ab positive - Previous infection Anti-HBc and Anti-HBs positive - HBeAg present in active or chronic infections

Answer 44

**virus:** hepacivirus **risk factors:** blood, sex, usually perinatal in babies (high HCV titre/HIV positive) **perinatal transmission (6% if mother HepC RNA +ve)** - develop 90% chronic infection, 10% transient viremia - breastfeeding NOT contraindicated - HepC Ab at 12-18 months **pathologenesis:** direct cytotoxicity to hepatocytes **clinical:** acute illness mild **serology:** HCV RNA diagnostic, anti-HCV Ab useful for chronic - chronic HCV: persistent anti-HCV and HCV RNA **treatment:** PEG IFN-a-2b + Ribavirin for 6/12 - 50% chance clearance **prognosis:** slowly progressive - 85% remain chronically infected with mild hepatitis - _children:_ 50-90% elevated LFTs, 40-60% positive RNA, cirrhosis 1-8%, HCC

Answer 45

**virus:** hepatitis D RNA virus **transmission:** blood **replication:** requires HBV co-infection or superinfection

Answer 46

**virus:** hepatitis E RNA virus **transmission:** faecal oral **epidemiology:** similar to HAV **clinical:** - peak \>15yrs - 3-8 weeks: lethargy, nausea and fatigue - usually self limiting - fatal in pregnant women and immunocompromised: fulminant liver failure

Answer 47

**incidence:** 80% liver cancer in kids - usually \<3yrs with abdominal mass **pathogenesis:** immature liver precusor cells usually R lobe **investigations:** elevated AFP, thrombocytosis, calcification **associated:** FAP, prematurity, BWS, Meckel's, Trisomy 18, cardiac anomalies, biliary atresia, Prader-Willi **metastasis:** lung, CNS treatment: resection, chemo, transplant

Answer 48

**neonate:** \>3.5cm BCM, size 4.5-5cm **child:** \>2cm BCM, size 6-8cm

Answer 49

**definition:** aganglionic bowel from anal sphincter **incidence:** 4:1 male to female **clinical:** - no meconium 24 hrs then abdominal distension, vomiting - 80% present first 6 weeks - causes 15-20% neonatal obstruction - infrequently enterocolitis **AXR:** no gas in rectum **diagnosis:** full thickness rectal biopsy

Answer 50

sporadic cause: failure migration of nerve cells causing absence ganglionic cells in submucosal and myenteric plexus epidemiology: 1/5000, M:F 4:1, assoc family history, T21, microcephaly, abnormal facies or palate location: extends proximally from anus, 80% short segment (only rectosigmoid), 15% long segment (proximal to rectosig) clinical: delayed mec \>48hrs, distension, bilious asp, constipation, enterocolitis, toxic megacolon (proximal dilation and bacterial colonisation) diagnosis: rectal biopsy, AXR treatment: surgical resection aganglionic segment

Answer 51

**indication:** bacterial overgrowth (eg short gut syndrome) **method:** give patient CHO load and measure expired hydrogen

Answer 52

**causes:** sporadic or familial **prognosis:** generally good if well at 12 months **poor prognosis:** - jaundice \>6months of age - acholic stools - persistent hepatomegaly - severe inflammation on biopsy - familial occurrence - low GGT (disorder of bile acid transport/synthesis)

Answer 53

**drugs:** monoclonal TNF antibody **use:** Crohn's, rheumatoid arthritis **side effects:** infection, fever, hypotension

Answer 54

**definition:** obstruction of lymphatic draininage of the intestine **cause:** _- congenital:_ Turners, Noonan’s, Klippel-Trenaunay syndrome _- secondary:_ constrictive pericarditis, HF, abdominal TB, retroperitoneal malignancies **pathophysiology:** - lymph rich protein leaks into bowel lumen clinical: - diarrhea/steatorrhea, nausea and vomiting - peripheral oedema - chylothorax or chylous ascites **diagnosis:** - hypoproteinemia, low albumin, IgA, IgG, IgM, transferrin, ceruloplasmin, clotting factors - loss of lymphocytes into gut (lymphopenia) - fat soluble deficiencies **investigations:** - small bowel contrast – thick, nodular folds - endoscopy – scattered white spots - histopath – dilated lymphatics at tip of villi **treatment:** - Low fat, high protein, medium chain triglyceride supplemented diet - octreotide - localised resection

Answer 55

**age:** 6months -3yrs - uncommon \< 3 months **clinical:** sudden onset severe paroxysmal colicky pain - associated straining effort with legs **diagnosis:** ultrasound **treatment:** air enema

Answer 56

**age:** 2-10yrs **risks:** 10-15% malignancy (multiple juvenille GIT polyps) **symptoms:** bright red painless rectal blessing during or after defaecation

Answer 57

**congenital lactase deficiency:** rare (\<50 cases), genetic, symptoms with lactose ingestion **primary adult-type hypolactasia (15% white adults)** - decline lactase activity by 3 yrs secondary lactase deficiency - post small bowel injury/infection/bacterial overgrowth - cows milk protein enteropathy **diagnosis:** H2-breath test or small bowel Bx and measuring lactase activity

Answer 58

**Liver clotting factors:** 2,5,7,9,10 - PT normal abnormal until 80% synthetic capacity lost - Factor VII has short half life (6hrs) and senses rapid change in liver function

Answer 59

**incidence:** 2-7% CRC patients **genetic:** AD loss of expression of MSH2 causing DNA mismatch repair **clinical:** increased risk colorectal cancer, endometrial cancer, digestive adenoma **diagnosis:** - 3 or more relatives with CRC - 2 successive generations - 1 or more colon cancers \<50 yrs - FAP excluded

Answer 60

**definition:** incomplete rotation of the intestine in fetal development **clinical:** volvulus in 1st week - bilious vomiting then abdominal distension - can progress to ischaemic bowel **diagnosis:** - XR double bubble sign - US: malposition superior mesenteric vessels - upper GI contract study

Answer 61

**definition:** form of lymphoma involving the mucosa-associated lymphoid tissue **pathophysiology:** 70-100% associated with chronic inflammation secondary to H.Pylori **diagosis:** GI biopsy **treatment:** - early stage disease curable with eradication H.Pylori - radiotherapy, chemotherapy

Answer 62

**incidence:** common congenital abnormality GIT **associations:** major malformations of umbilicus, GIT, CNS, CVS **rule of 2’s:** - 2% population - M:F 2:1 - 2 feet from ileocaecal valve - 2 inches long - complications in 2% of patients **clinical** - usually clinically silent - 50% present \<10yrs painless lower GI bleeding - ulceration small bowel from acid secretion of ectopic gastric mucosa in the Meckel’s (25%) - chronic or acute - meckel's can be lead point for intussusception/volvulus **diagnosis:** nuclear med 99m technetium detects gastric mucosa (sensitivity 85-90%) - mesenteric arteriography: anomalous superior mesenteric artery branch feeding diverticulum - HRCT **management:** resect if symptomatic/palpable abnormality

Answer 63

**pathogenesis:** - increased RBC breakdown: x2-3 production bilirubin - decreased UGT activity until 14 weeks - increased reabsorption due to sterile gut

Answer 64

**incidence:** rare, onset 1 week **allergens:** breast milk, cow milk, soy, extensively hydrolysed formula **clinical** irritability, feed refusal, vomiting, diarrhoea **treatment:** AA formula

Answer 65

**S:** structural: biliary atresia, choledochal dyst, Caroli disease **M:** metabolic: galactossaemia, CF, alpha-1-antitrypsin, bile acid transport defect **I:** infection (TORCH/sepsis), idiopathic **T:** TPN **E:** endocrine (hypothyroidism/hypopituitarism)

Answer 66

**hydrolized protein**: peptides with added AAs and fat (primarily MCTs) - _indications:_ cow milk/soy protein allergy, galactosemia **free AA acid formulas:** non-allergic free AAs - _indications_: multiple food allergies, severe protein allergy, malabsorption, SBS, eosinophilic GI disorders - eg. neocate, elecare **low long chain fatty acid** - _indications:_ FA met disorder, fat malabsorption, chylothorax, lymphangiectasia - eg. enfaport, portagen, monogen

Answer 67

**source:** 80% bilirubin from breakdown Hb **metabolism:** - bound to bilirubin - dissociates for uptake into hepatocytes - UGT catalyses conjugation with glucuronic acid for excretion in bile - excreted into bile and broken down bacterial enzyme urobilin - beta-glucuronidase deconjugates allowing reabsorption into entereohepatic circulation

Answer 68

**mother:** HepBsAg positive **treatment of infant:** - immunise at birth then 2,4,6 and 12 months - hep B IVIg within 24 hrs of birth **testing:** 9-15 months

Answer 69

**deficiency:** pellagra (dementia, dermatitis, diarrhoea) - aggression, dermatitis, insomnia, confusion, diarrhoea **use:** essential for electron transport

Answer 70

**prevalence:** 20% of obese children - most common liver disease in children **risk factors:** obesity, insulin resistance **pathogenesis (spectrum)** - fat accumulation in hepatocytes w/o inflammation - fibrosis (simple hepatic steatosis) - hepatic steatosis with necroinflammation (steatohepatitis) termed NASH **symptoms:** may have RUQ pain, hepatomegally **diagnosis:** - _US_: increased echogeneity - _serum_: elevated LFTs - biopsy **management:** weight control **prognosis:** 1/2 NASH progress to cirrhosis

Answer 71

Diameters Cricopharyngeal sphincter: narrowest part 15cm from incisors Constrictions at aortic arch (22cm), left main bronchus (27cm) and lower oesophageal sphincter

Answer 72

**definition:** neonatal conjunctivitis in the 1st month **pathogens/treatment:** _neisseria gonorrhoea:_ - day 0-5 - purulent discharge/inflammation - treat: bacitracin, 7 days IV ceftriazone _chlamydia trachomatis:_ - 5 days -2 weeks - more watery - treatment: AB drops, PO erythromycin to prevent resp disease **less common pathogens:** - HSV-2, staph aureus, **complications:** untreated may develop corneal ulceration

Answer 73

**definition**: isotonic with equimolar concentrations of sodium and glucose **properties:** - osmolality 200- 310 mmol/L - glucose \<20 g/L (111 mmol/L) - sodium 60- 90 meq/L - potassium 15- 25 meq/L - chloride 50- 80 meq/L **mechanism water absorption:** passive diffusion across osmotic gradient determined by **1.** Na/H exchanger **2.** electrochemical gradient **3.** Na coupled transport **role of starch:** increased non-absorbed CHO in colon is fermented into SCFA which are readily absorbed and increase Na reabsorption

Answer 74

**causes:** presence of non-absorbable solutes in the gut (e.g. lactose or fructose in intolerance) **pathophysiology:** - intestinal damage (viral gastro) - reduced functional absorptive surface (coeliac) - defects in enzymes/nutrient carriers (lactase def) - decreased transit time (functional) **clinical:** - STOPS when cease enteral feeds - volume SMALLER \<200mls **investigations:** - reducing substances PRESENT - stool pH \<6 - stool Na \<60 (water drawn in dilutes) - stool osmotic gap \>100

Answer 75

**function:** secretes alkaline juice after eating - exocrine function under hormonal (secretin and CCK)/neuronal control **Stimulated:** - _secretin:_ released duodenal S cells in response to acid (stimulates pancreatic ductal cells) - _CCK_: released duodenal I cells response to fats + proteins (stimulates acinar cells/GB contraction) **inhibited:** - somatostatin: duodenum/delta cells of pancreas **pancreatic enzymes:** - trypsinogen/chymotrypsinogen - carboxypeptidase (protein) - elastases (break down the protein elastin) - lipase (triglycerides and fatty acids) - amylase (starch, glycogen, other carbs) - sterol esterase, phospholipase, nuclease **insufficiency causes maldigestion:** - fat globules when \>90% exocrine function lost **tests:** - measuring pH/enzyme content of duodenal fluid after stimulation pancreas (e.g.meal/secretin/CCK) - serum trypsinogen - faecal fat ( \>90% enzyme function lost) - faecal chymotrypsin/faecal elastase-1

Answer 76

**cause:** 30% idiopathic, trauma, cholelithiasis **pathogenesis:** premature activation of trypsinogen and pancreatic proenzymes causing autodigestion **diagnosis:** serum lipase rises 4-8hrs, peaks 24-48 hrs, elevated 8-14 days - US: evidence of inflammation **complications:** death, pseudocyst, abscess **treatment:** NBM 24hrs, octreotide DOESN'T WORK

Answer 77

e.g. pepti-junior, alfare **formula:** di/tri peptides, AA, vegetable oil/MCT, carb maltdextrin (lactose free), low osmolarity **indications:** fat malabsorption, intolerance whole protein, severe chronic diarrhoea

Answer 78

**increased production (haemolysis)** - autoimmune (ABO/Rh) - RBC membrane defects (spherocytosis/elliptocytosis) - RBC enzyme defects (G6PD, pyruvate kinase def) - sepsis **decreased clearance (defects UGT)** - Crigler Najar/Gilbert - maternal DM - congenital hypothyroidism - galactossemia - structural (biliary atresia, alagille, caroli) **increased enterohepatic circulation** - breast milk

Answer 79

**metabolism:** - precursor pepsinogen secreted chief cells - converted by HCl acid to pepsin **function:** breaks down proteins

Answer 80

**incidence:** uncommon **causes:** - \<10yrs: medications, more common gastric - \>10yrs: H-pylori, duodenal - 20% idiopathic - secondary H.pylori, medications, Zollinger-Ellison, SBS **symptoms:** pain (alleviated by food), NV, perforation, iron def, ITP, SIDS **investigations:** H.pylori stool antigen assay, urea breath test, H.pylori IgG serology (low sens/spec), endoscopy **management:** triple therapy (PPI+clarithomycin+amoxi/metro)

Answer 81

**definition:** portal vein pressure \>5mmHg or portal vein:hepatic vein gradient \>10mm **symptoms:** splenomegally (with thrombocytopaenia, anaemia, leukopaenia), varices (oeso, gastric, rectal), ascites, encephalopathy **causes:** cirrhosis, pre-sinusoidal (portal vein thrombosis), post-sinusoidal (budd-chiari, venoocclusive disease) **management:** variceal banding, transjugular intrahepatic portosystemic shunt (TIPSS)

Answer 82

**incidence:** very very rare 1:60,000 **definiton:** complete inability to digest lactose from infancy **pathophysiology:** complete absence of lactase

Answer 83

**incidence:** 70% associated with UC - complicates 1-3% UC **symptoms:** jaundice, hepatomegally, cholestasis, fat malabsorption, bone disease **associated:** cholangiocarcinoma (10-15%) **investigations:** elevated LFTs (ALP highest), increased IgM, pANCA positive **ERCP/MRCP**: short strictures in bile ducts with dilatation in between normal zones (beadin) **treatment:** ursodeoxycholic acid, liver transplant

Answer 84

**Metoclopramide** - _mechanism:_ D2 antagonist CNS and gut - _side effects_: restlessness, dystonic reactions **Erythromycin** - _mechanism_: motilin receptor agonist - _side effect_: prolonged QT, c.difficile, pancreatitis

Answer 85

3 main causes: 1) Mucosal disease with protein loss across mucosa eg. IBD, ulcer, lymphoma 2) Lymphatic obstruction causing protein rich chyle eg. primary intestinal lymphangectasia, secondary obstruction due to cardiac disease, infection, neoplasm 3) Idiopathic alteration in mucosa permeability eg. gastroenteritis, coeliac, Zollinger Ellison, SLE Stool alpha 1 antitrypsin is a marker (resistant to proteolysis and degradation in the bowel)

Answer 86

**drugs:** omeprazole, pantroprazole **pharmacology:** irreversibly/noncompetibly block parietal cell H/K ATPase and decrease HCC secretion **use:** GORD, PUD, gastritis

Answer 87

**definition**: sugars capable of reducing oxidizing agents in alkaline solution - e.g. glucose, fructose, maltose, lactose - non reducing sugars: sucrose

Answer 88

symptoms: - hypophosphataemia, hypokalaemia, hypomagnesia, hyperglycaemia - vitamin depletion - volume overload/oedema: Na/fluid reabsorption in kidneys mechanism: surge of insulin pushes/PO4/K/Mg into cells complications: CVS , resp failure (hypophosp), muscular weakness, raised liver transaminases (increased fat deposition), diarrhoea, neurological prevention: slow feeding, careful monitoring, electrolyte replacement

Answer 89

**definition:** dsRNA virus family reoviridae **clinical:** foul smelling non bloody diarrhoea for 3-8 days - associated nausea, vomiting, fever - secondary lactose intolerance for weeks **pathophysiology:** Day 1: infects enterocytes of villous epithelium jejunum/ileum causing cell damage and loss of fluid/salt Day 2-5: adjacent villi fuse reducing SA Day 6-10: normal architecture - loss of brush border enzymes with loss ability to digest complex sugars/CHO causing lactose intolerance - secretory diarrhoea via non-structural glycoprotein NSP4 enterotoxin: calcium ion dep chloride secretion and disrupts water reabsorption - enteric nervous systemic activation wiuth secretion **diagnosis:** antigen stool immunoassay - 1-4 days 94% detected - 4-8 days 76% detected - \>2 weeks occassional

Answer 90

**definition:** gram negative rod of enterobacteriacae family **source:** contaminated food, hands, water **clinical:** - fever diarrhoea, anorexia, headache, stomach pain, vomiting - mucousy/bloody stool - 5% develop bacteraemia/meningitis/osteomyelitis (greater\<3m) **pathophysiology:** - incubation 12-36 hours, duration 4-7 days - enterocolitis with diffuse mucosal inflammation/edema with microerosion/abscesses - attaches epithelial cells via fimbriae and invades cells by bacterial mediated endocytosis and remain in phagosome - induce inflammatory response with IL8 secretion, neutrophil recruitment and pro-inflammatory mediators **diagnosis:** faecal PCR **treatment:** fluoroquinolones

Answer 91

Autosomal recessive chromosome 7 Skeletal (\>2yrs), Haematological Normal sweat chloride 30% develop myelodysplastic syndrome Neonatal sepsis secondary to neutropaenia Lipomatous changes in pancrease: 50% pancreatic insufficiency age 4-5yrs

Answer 92

Causes: - electrolyte and water secretion into intestinal lumen - stimulates Cl secretion or inhibition of NaCl absorption bacterial toxins: bacillus cereus, clostridium perfringens, Enterotoxigenic Ecoli, cholera, giardia lamblia, crytosporidium, rotavirus Feeds: CONTINUES when cease enteral feeds \*\*\* Volume: LARGE \>200mls/day Features: * NO reducing substances * pH \>6 * Stool Na \>90 * Osmotic gap \<50

Answer 93

definition: shigella bacteria gram negative rod **source:** food, faecal oral route **clinical:** pain, fever diarrhoea with mucous/pus/blood, mucosal ulcerations - assoc seizures **timing:** onset 12-96hr lasting 5 to 7 days **pathogenesis:** - attach to and penetrate intestinal mucosa causing inflammation/desquamation - spread to adjacent cells via fimbriae - induce inflammatory reaction **treatment:** bactrim if necessary

Answer 94

Loss \>50% bowel Generalised malabsorption disorder of specific nutritional def Proximal jejunum main site CHO, protein, Fe, water soluble vitamin absorption Fat over large length small bowel Symptoms: watery diarrhoea, cholestatic liver disease, gastric hypersectrion, ulcers, bacterial overgrowth, nutrient/vitamin def, enteric hyperoxaluria (calcium binds fat in steatorrhoea) causing kidnet stones Treatment: TPN, trophic feeds

Answer 95

0.02-0.1% live births 80% develop in neonatal period Most common cause of intestinal failure (unable to achieve complete nutrition without supplementation) Malabsorption marcro/micronutrients caused by massive resection small intestine Causes: NEC (35%), mec ileus (20%), abdominal wall defects (12.5%), intestinal atresia (10%), volvulus (10%) Mortality 20-40% Management: PN, enteral nutrition (high fat, complex CHO), H2 blockers, vitamins, serial transverse enteroplasty

Answer 96

**onset:** 30-8hrs post food **mechanism**: staph aureus toxin **clinical:** severe vomiting +/- diarrhoea - resolves 24-48 hours

Answer 97

**equation: 290-2(Na+K) = 50-100mosm/kg** \*290 value of plasma osm **Interpretation** - if \>100mosm/kg: osmotic diarrhoea - if \<50mosm/kg: secretory diarrhoea **NB. Sodium\>70mmol/l suggestive of secretory diarrhoea**

Answer 98

**definition:** rare AR absence of sucrase in small intestine **clinical:** - diarrhoea, abdominal pain, poor growth with exposure to sucrose or glucose (non lactose formula/pureed food) **diagnosis**: - H2 breath test - NO reducing substances are present (sucrose isn’t a reducing sugar) - direct enzyme assay on small bowel Bx **treatment:** dietary restriction

Answer 99

**drug:** sulfapyridine and mesalamine **pharmacokinetics**: - prodrug: 1/3 absorbed small intestine, 2/3 colon (splits into 5-ASA and SP) **use:** Crohn's, ulcerative colitis **toxicity:** anorexia, nausea, vomiting, sulfur toxicity

Answer 100

mucus secreting cells of ectopic gastric mucosa take up pertechnetate sensitivity 85%, specificity 95%

Answer 101

Many BAs per day but otherwise well + thriving Daily, painless \>3 large unformed stools, \>4 week duration Rx: trial lactose and low fructose (low fruit juice) diet

Answer 102

18% to 67% of infants who receive prolonged courses of PN develop liver injury and cholestasis RF: low birthweight, long PN therapy, sepsis, bacterial overgrowth of the small intestine, and intestinal failure Cause: The soybean-based lipid emulsion component of PN. Treat: enteral feedings as early as possible to stimulate bile flow, gallbladder contraction, and intestinal motility. Ursodeoxycholic acid is theoretically of benefit by stimulating bile flow; however, there is no evidence of its efficacy in PNAC.

Answer 103

* TOF is a common congenital anomaly of respiratory tract * 1 in 3500 * Typically occurs with oesophageal atresia * OA and TOF are classified by anatomy * Type C – account for 84% * Defect in lateral septation of the foregut into oesophagus and trachea * Associated with VACTERL (vertebral anomalies, anal atresia, cardiac anomalies, TE = tracheoesophageal fistula, renal anomalies, limb anomalies) Clinical features * Depends on presence or absence of OA * In cases with OA (95%) – polyhydramnios occurs in 2/3^rds of pregnancies * However many are not detected antenatally * Infants with OA because symptomatic immediately after birth * Infants with H type – * May present early if defect is large with coughing and choking associated with feeding as milk is aspirated * However smaller defects may not be symptomatic in newborn period * Can be diagnosed from 26 days to 4 years * Prolonged history of mild resp distress associated with feeding and recurrent pneuomina Diagnosis * Pass catheter into stomach: not passed further than 10-15cm * CXR: catheter curled up in upper oesophageal pouch * Distal TOF can be seen on lateral chest CXR – both views will show gas filled GIT * For isolated TOF – upper GIT series with barium & endoscopy & bronchoscopy Management * Surgical ligation of fistula * With OA need to anastomose oesophagus Outcome * For isolated TOF – generally good * With AO and TOF it is more guarded and depends on associated abnormalities * Higher mortality if cardiac disease present * Complications – anastomotic leak, oesophageal stricture, recurrent fistula * GORD and aspiration

Answer 104

usually asymptomatic types: simple/solitary, polycystic, parasitic (hydatid cyst), neoplastic (cystadenoma, cystoadenocarcinoma, mets), duct related (Caroli, bile duct dupication), false cyst

Answer 105

**definition:** elevated ALP in absense liver/bone disease **diagnosis:** 5x normal and decreases \<3 months **pathogenesis:** unknown **investigations:** Ca, Ph, ALT, AST, GGT, bilirubin, vit D, PTH, urea, Cr

Answer 106

**Phototherapy** - isomerisation to lumirubin (more soluble/less toxic) - fluorescent blue light Side effects: dehydration, rashes, loose stool, hyperthermia, bronze baby **Exchange transfusion** - replace 85% circulating RBCs to decrease bilirubin by 50% - also infuse 1g/kg albumin - above threshold OR signs of kernicterus Side effects: infection, DIC, GVHD, thombosis, EUC abnormalities

Answer 107

PPI, clarithromycin and amoxycillin

Answer 108

**incidence:** 11/100,000, M\>F 1.8:1 **pathology:** contiguous large bowel mucosal, NEVER PERIANAL LESIONS **risk factors:** twice as common in non-smokers **clinical:** **-** diarrhoea with bleeding/mucous - abdominal pain - urgency, tenesmus - lethargy, anorexia, fever - pyoderma gangrenosum (50%), erythema nodosum (4%) **Fulminant colitis**: \>5 bloody stools per day **complications:** increased malignancy 8-10yrs post diagnosis, toxic megacolon **diagnosis:** pANCA (70%), ASCA **treatment:** 5-ASA, steroids, immunomodulators, colectomy (25% within 5 yrs dx)

Answer 109

^Causes: ^{- breast milk: benign, onset d3-5, persists >1wk, high levels beta glucoronidase causes deconj of bilirubin} ^{- breast feeding} ^{- haemolysis} ^{- Crigler-Najjar} ^{- Gilberts}

Answer 110

Toxin: 5 binding (B) subunits and 1 active (A) subunit - B subunits bind GM1 ganglioside receptors on the small interstinal mucose - A subunit enters cells and activate adenylate cyclase, increasing cAMP, blocking absorption of NaCl by microvilli - increased secretion Cl/water by crypt cells

Answer 111

**causes:** poor intake in developing countries, fat malabsorption **clinical:** - _ocular_: night blindness, retinopathy, xeropthalmia - _skin_: hyperkeratosis, destruction hair follicles - _other_: poor bone growth, infections, abnormal tooth enamel development

Answer 112

**deficiency:** beriberi - weight loss, emotional distubance, Wernicke's, weakness, arrythmia, weakness

Answer 113

**source:** meat/dairy **stores:** 50% liver, 3 yrs until deficiency develops **absorption** - B12 unbound to protein and binds R factors in stomach - B12 unbound R factors by pancreatic proteaases and bind to IF - absorbed _terminal ileum_ as B12-IF complex **plasma:** bound to transcobolamins (TC I, II, III) - TC II: most important, carries B12 to liver/BM, reflects tissue stores **cells:** - receptor mediated endocytosis into cells - converts proprionyl CoA to succinyl CoA - transfers methyl group from methylTHF to homocysteine to form methionine

Answer 114

**congenital causes:** _transcobalamin deficiency:_ AR - failure to absorb/transport B12 with normal serum B12 because T I/III unaffected - manifests first weeks of life - treatment: large parenteral doses B12 **clinical:** - anaemia, glossitis, stomatitis, jaundice, bleeding, infections - neurological: peripheral neuropathy, optic atrophy, MR, subacute cord degeneration **diagnosis:** - macrocytic anaemia \>100, large/ovoid RBCs, anisocytosis, poikilocytosis, low reticulocytes - low B12, normal folate, increased urine methylmalonic acid/homocysteine

Answer 115

**deficiency:** ariboflavinosis **clinical:** glossitis, angular chelitis, light sensitivity, dermatitis

Answer 116

Deficiency: irritability, seizures, anaemia

Answer 117

**causes:** anorexia, neurodevelopmental delay **clinical:** (scurvy) - _skin_: hyperkeratosis, perifollicular haemorrhage, petechiae, ecchymoses, gingivitis _other_: fatigue, arthalgias, anorexia, neuropathy, dyspnoea, hypotension, anaemia, impaired wound healing

Answer 118

Deficiency: Rickets (up ALP), hypocalcaemia, osteomalacia, infantile tetany - risk factors: poor sunlight/intake, exclusive breastfeeding, maternal def, prematurity, obesity, CRF, malabsorption, liver failure, drugs (anticonvulsants, antiretrovirals, steroids, ketoconazole) Excess: hypercalcaemia, azotemia, poor growth, NVD, calcinosis

Answer 119

**causes:** fat malabsorption **clinical:** - _spinocerebellar syndrome_: ataxia, hyporeflexia, loss of proprioreceptive/vibratory input - _haem_: haemolytic anaemia **treatment:** reversible\<4yrs

Answer 120

Deficiency: haemorrhage (factors II, VII, IX, X)

Answer 121

**incidence:** 1/30,000 **genetics:** AR, chromosome 13 ATP7B **mechanism:** defect in copper excretion with accumulation in liver/brain **symptoms:** - _ocular_: kaiser-fleisher rings (50%), sunflower shaped cataracts - _GI_: abdo pain, jaundice, hepatomegaly, portal HTN - neurological sx in 20's: gait, tremor, dysarthria, basal ganglia copper deposition - _other:_ haemolytic anaemia, renal failure **investigations:** low serum copper, low plasma ceruloplasmin, elevated transaminases AST\>ALT, low ALP, raised urinary/liver copper, thrombocytopaenia, coagulopathy p**rognosis:** HCC, liver failure

Answer 122

**causes:** crohn's CF, sickle cell, liver disease, acrodermatitis enteropathica (congenital defect in absorption) **clinical:** - erythemtous/vesiculobullous rash to genitals and cheeks - diarrhoea - poor growth - alopecia - decreased ALP

Answer 123

**incidence:** 5/100,000 (25% \<18 years) **pathology:** GI tract, patchy, transmural, perianal disease, oral lesions (10%) **clinical:** - abdominal pain, diarrhoea, rectal bleeding - fevers, weight loss - pyoderma gangrenosum **complications:** strictures, fistulas, abscess **treatment:** enteral tx, 5-asa, steroids, azathioprine, MTX, antibiotics, TNF mono Ab

Answer 124

**metabolism:** - 0.3% have low TPMT activity - 11% intermediate TPMT activity **high levels TGN:** increased therapeutic index/BM suppression **high 6-MMP:** increased hepatotoxicity