Gastroenterology Flashcards
What disorders are characterised by vomiting of undigested food?
Achalasia
Delayed gastric emptying
Rumination
What does bilious vomiting suggest?
GI obstruction beyond the duodenum (eg malrotation, volvulus, obstruction eg mec ileus)
Best test for diagnosis of chronic vomiting
Endoscopy
Describe cyclic vomiting syndrome
Paroxysms of vomiting followed by symptom free periods (weeks to mths)
Strong association with fam hx migraines
Median age onset 5 yrs
Thought due to dysfunction of vasovagal axis
2016 Rome IV criteria cyclical vomiting syndrome (3)
2 or more periods of unremitting paroxysmal vomiting with or without retching, lasting hrs to days, within a 6 mth period + 3 episodes in past yr
Episodes are stereotypical for each pt
Episodes separated by wks to mths with return to baseline btwn
2016 Rome IV criteria for rumination syndrome (3)
Repeated regurgitation and rechewing or expulsion of food that occurs soon after a meal
Not preceded by retching
Can’t be explained by another disorder
Gastroparesis definition
Delayed gastric emptying in the absence of mechanical obstruction
Most common cause is post-infectious (viral gastro) which causes neuropathy of autonomic ganglia
Other causes = T1D, gastric hypomotility (eg in kids with static encephalopathy)
Symptoms gastroparesis
N&V (undigested food many hrs after a meal)
Abdominal pain
Early satiety
Abdominal distention
+/- Weight loss
Symptom of h pylori infection
Night time awakening from pain
Differential dx - pain with eating
Biliary disease eg cholecystitis
Pancreatitis
Describe functional abdominal pain
Peak incidence 7-10 yrs
3 or more episodes in last 3 mths that interferes with activities of daily living
Gth and development are NORMAL
School absenteeism big issue
Pain worse with environmental stressors, temperament, secondary gain
Also called pain-predominant functional gastrointestinal disorder (FGID)
Features on hx that suggest abdo pain is organic not functional
Unexplained intermittent fevers
Wakes pt at night
Bilious or protracted vomiting
Bloody or chronic loose stools
Wt loss or poor wt gain
Deceleration linear gth
Oral ulcers
Localised RUQ or RLQ tenderness
Costovertebral angle tenderness
Hepatosplenomegaly
Perianal abnormalities
Abdo pain patterns in functional disorders
Functional abdo pain syndrome - periumbilical + normal gth and appetite
Functional dyspepsia - midepigastric + correlates with meals
IBS - pain improves with defacation and frequent changes in stool caliber or regularity
Abdominal migraine - pain poorly localised, may be dull to severe + usually fam hx migraines
Typical infectious diarrhoea clues
Recent travel - E coli, Giardia
Exposure to reptiles - Salmonella
Fever + high WCC - Shigella
HUS - E coli O157:H7
Lake swimming, drinking - Giardia
Pork intestine - Yersinia
Recent abx use - C diff
Chicken - Campylobacter
Differential dx chronic diarrhoea
IBS
Functional diarrhoea (toddler’s)
Post enteritis syndrome
Carbohydrate malabsorption syndrome
IBD
CF
Giardia, other parasites
Organic causes constipation
Thyroid disorders
Hirschsprung disease
CF
Spinal dysraphism
Other neurological
Describe infant dyschezia
Up to age 9 mths
> 10 mins straining or crying before successful or unsuccessful passage of stools
Due to poor coordination btwn intraabdominal pressure and relaxation of pelvic floor
Normal stool consistency ie not hard
Explain functional constipation
Most common cause of constipation
2 peaks - toilet training and start of school
Also due to painful defacation, anal fissures, perianal infections
Associated with abdo pain, soiling, reduced appetite
Antenatal clue for tracheoesophageal fistula and oesophageal atresia
Polyhydramnios (except in H type)
Most common form of TOF
Type C
Blind, upper OA with a fistula between the lower oesophagus and lower portion of the trachea.
Will present with excessive oral secretions and appears to be choking frequently, esp when feeding.
Dx: attempt to pas NGT
Mx: keep at ~30 degrees, surgery
Describe xray finding of isolated oesophageal atresia aka no fistula between oesophagus and distal trachea
Flat, gasless abdomen (not seen in TOF) - no connection from trachea to oesophagus and no air entry via oesophagus
Proportion of patients with TOF that have other congenital abnormalities
1/3 (esp VACTERL)
Describe achalasia
Disorder of the oesophagus characterised by incomplete relaxation of the LOS and a lack of normal oesophageal peristalsis (motor not anatomic problem).
Like due to autoimmune mediated loss of ganglion cells and/or dorsal motor nuclei reduction of vagus nerve signals.
Mean age of presentation is 9 yrs.
Treatment = myotomy
Congenital disorder associated with achalasia
Allgrove syndrome
GORD red flags
Systemic: FTT, feeding refusal, dystonic neck posturing, dental erosions, anaemia
Resp: wheezing, stridor, cough, hoarseness, recurrent aspiration pneumonia
GI - oesophagitis, oesophageal stricture, haematemesis, dysphagia
Diagnosis of oesophagitis (GORD, eosinophilic, infectious)
Upper endoscopy WITH biopsy
Surgical management severe GORD
Nissen fundoplication - fundus of the stomach is pulled up and wrapped around the lower oesophagus, forming a valve
Most common cause of dysphagia or food impaction in children
Eosinophilic oesophagitis
Adenomatous polyps
Gland-like growths that develop on the mucous membrane that lines the large intestine
Hamartomatous polyp
Juvenile polyp with 3 classical histological features
1) dilated cystic glands with retention of mucous and lined by tall columnar epithelium
2) markedly expanded lamina propria
3) diffuse chronic infiltration of inflammatory cells
Describe prehepatic jaundice
Excess bilirubin overwhelms the ability of the hepatocyte to conjugate bilirubin
Describe hepatic jaundice
Failure of bile formation or excretion at the cellular level
Describe post hepatic jaundice
Interruption of bile drainage into biliary system
Eye finding in Wilson’s disease
Kayser-Fleischer rings (copper deposit)
Differential dx UN-conjugated bilirubin
Haemolysis
- Haemoglobinopathies eg sickle cell, thalassaemia
- Enzyme defects (eg GDPD)
- RBC membrane disorders (eg hereditary
spherocytosis)
Inherited
- Gilbert syndrome
- Crigler-Najjar syndrome
Differential dx conjugated bilirubin
1) Infections (hep A-E, EBV, CMV)
2) Biliary tract disease (choledochal cyst, cholelithiasis/choledocolithiasis, sclerosing cholangitis, Alagille syndrome)
3) Drug induced
4) Metabolic liver disease (Wilson’s, alpha-1 antitrypsin deficiency, Dubin-Johnson syndrome, progressive familial intrahepatic cholestasis
5) Autoimmune
What radiological imaging is best for choledochal cysts?
US shows intra and extra hepatic biliary tree dilatation
MRI cholangiopancreatography useful for determining the anatomy
Cancer risk post choledochal cyst surgical correction
17.5% risk of biliary malignancy
Most are cholangiocarcinomata
What is the ductal plate (embryology)
Forms at 8 wks of gestation and consists of hepatic precursor cells that remodel through fetal life to form the intrahepatic biliary tree
Describe Caroli disease
Congenital dilatation of the larger, segmental intrahepatic bile ducts
If occurs with congenital hepatic fibrosis = Caroli syndrome
AR condition
Presents in adolescence or adulthood with recurrent cholangitis and abscesses
Rx - abx aimed at cholangitis, partial hepatectomy
Complications - cholangiocarcinoma, amyloidosis
Genetics of Alagille syndrome
20p12 deletion
Also referred to as arteriohepatic dysplasia, Watson-Miller syndrome, syndromic duct paucity
AD inheritance with variable penetrance
Caused by mutations in single gene JAG1 on chr 20p (also NOTCH 2)
Alagille clinical features (non-facial)
CVS: Peripheral pulmonic stenosis > tetralogy of fallot
Vascular: Vascular anomalies (including intracranial)
GI: Neonatal cholestasis; chronic cholestatic liver disease with paucity of small intrahepatic ducts
MSK: Butterfly vertebrae; abnormal radius/ulna
Ophthal: Posterior embryotoxon of the eye (white ring of Schwalbe and iris strands that partially obscure the chamber angle)
Alagille facial features
Prominent forehead
Moderate hypertelorism
Saddle or straight nose
Small, pointed chin
Long-term management issues with Alagille
Kasia portoenterostomy CI as issue is with ducts within the liver, not the biliary duct
Prone to intracranial bleeding even with minor head trauma
Liver transplant indicated for hepatic failure, severe growth failure, or intolerable itching unresponsive to medical therapy
How is hep A transmitted from person to person?
Fecal-oral route, generally among household and daycare contacts
Can also be sexually transmitted
No transplacental transmission
Incubation is 15-50 days
Which lab test is used to diagnose acute hep A?
High titres of IgM abs directed against HAV (anti-HAV IgM) (IgG indicates previous infection)
The ab is detected in the serum 5-10 days
What can be given to household contacts to prevent spread of hep A once a case has been identified?
HepA vaccine OR immunoglobulin (IG), preferably within 2 weeks of exposure
HepA vaccine preferred for > 12 mths
IG preferred for < 12 mths
IG is only good in Hep A, NOT Hep B
How is hep B transmitted?
Sexual contact
Contaminated body fluids and needles
Transplacentally
Incubation = 1-6 mths
Hep B - DNA or RNA?
Hep B is the ONLY hepatitis virus composed of DNA
Which lab test indicates immunity to hep B?
Which lab test correlates with increased infectivity of the pt with hep B?
What is the window period for hep B infection?
Hep B is associated with which autoimmune reaction?
Once infected with acute hep B, who is more likely to develop chronic hep B - an infant or an adolescent?
In adults, chronic hep B is associated with which 2 serious conditions?
Which is more likely to cause chronic hepatitis - B or C?
Hep C - only 1% of adults with hep B develop chronic disease, cf 70-80% hep C infections
Hep B has higher viral counts, hep C lower (consistent with its more insidious nature - 25% asymptomatic, multiple phenotypes)
Extra hepatic manifestations of hep C?
Small vessel vasculitis with glomerulonephritis and neuropathy
Mixed cryoglobulinaemia - small vessel (leukocytoclastic) vasculitis with a rash consisting of purpura or crops of purple papules
Porphyria cutanea tarda
Which coinfection does hep D require to cause infection?
Hep B - Hep D is an RNA virus that requires a concomitant or previously existing HBV infection to become pathogenic. Immunity to hep B implies immunity to hep D.
Diagnose by anti-HDV IgM
How is hep E transmitted?
Single stranded RNA virus spread through fecal oral route.
Found in East and Sth Asia, Africa and Central America, frequently due to contamination of water after monsoon flooding
Consider in cases of hepatitis in returned traveller with neg hep A, B and C serologies
In whom is hep E most virulent?
High risk for fulminant hepatitis in 3rd trimester of pregnancy, with a 20% maternal fatality rate
Otherwise it’s an acute, self-limiting virus with resolution in 1-6 wks
Liver disease in EBV?
Tends to be mild and transient but can occasionally be severe and long-lasting, particularly in those who are immunocompromised
Presenting features of coeliac disease
Growth faltering
Diarrhoea
Mouth ulcers
Rash - dermatitis herpetiformis (10-25%)
Symptoms Crohn’s
Abdo pain, diarrhoea, fevers, wt loss
Extra-intestinal:
- arthritis
- uveitis
- fatigue, anaemia
- rashes - pyoderma gangrenosum, erythema nodosum
Passage of indirect inguinal hernia (common)
Gut passing through the peritoneal channel made by the processus vaginalis
Passge of direct inguinal hernia (rare)
Bulge through posterior wall of inguinal canal
Rare unless in setting of underlying connective tissue disorder
Complications post inguinal hernia repair
Recurrence - common
Testicular atrophy - possible if incarcerated, also may be secondary to herniotomy
Hydrocele - rare
Describe juvenile polyps
- 90% of polyps in childhood
- Benign hamartoma
- Present age 2-6 yrs with painless PR beeding
- 5% prolapse, 10% associated with abdo pain
- Most polyps are solitary and located within 30cm of anus
- Not premalignant
Describe juvenile polyposis
- Rare condition in pts with more than 5 juvenile polyps
- Sx – diarrhoea, rectal bleeding, intussusception, anaemia, prolapse, FTT
- May be sporadic or familial, AD inheritance
- Polyps can occur throughout GI tract
- 17% malignant potential
- Prophylactic colectomy may be advised
Describe FAP and Gardner syndrome
- FAP and Gardner syndrome (variant of FAP) – AD inheritance
- Garder syndrome – also develop other tumours outside GI organs incl. epidermoid cysts, bony lesions, subcutaneous tumours
- Multiple polyps develop (> 100), usually in 2nd decade
- Gastric and duodenal polyps develop in up to 50%
- Increased risk of thyroid and liver tumours
- Most diagnosed via screening
- Both carry high risk of colonic carcinoma (100%)
- Prophylactic colectomy at the end of the 2nd decade is advised
Describe Peutz-Jegher syndrome and association to polyps
- AD inheritance
- Consists of hamartomatous polyps that can occur throughout GI tract, but usually in small intestine
- Associated with hyperpigmentation of buccal mucosa and lips
- Pts with family history will often present with abdo pain caused by intussusception 2o to bowel polyps
- Increased risk of pancreatic, ovarian, breast, cervical and testicular tumours
Describe biliary atresia
- Congenital liver disorder where bile ducts are stenosed, blocked or absent. Results in progressive obstructive jaundice and liver failure
- Conjugated ↑ bili
- Presentation: Jaundice, pale stools, dark urine, unwell.
- Jaundice initially responds to phototherapy, later conj bili resistant to phototherapy
- Presents early, latest 8 weeks
- Mx: Kasia procedure, liver transplant
Describe Crigler Najjar syndrome (jaundice)
- Rare, AR
- Defects of bilirubin metabolism, due to enzyme defect
- Unconjugated ↑ bili
- Presentation: early (<24h) severe neonatal jaundice, but may be cause of persistent jaundice in 1st weeks of life
Describe galactosaemia (jaundice)
- Rare, AR metabolic disorder
- Sugar galactose can’t be broken down by body
- Unconjugated ↑ bili
- Presentation: ↑ bili, wt loss, vomiting, ↑ susceptibility to infection esp E Coli
Describe Gilbert syndrome (jaundice)
- Common, mild disorder of bili metabolism
- Unconjugated
- Usually asymptomatic
- Can result in mild episodes of clinically apparent jaundice in response to physiological stressors
- Will have isolated ↑ bili with normal LFTs
Osmotic v secretory diarrhoea
