Gastroenterology Flashcards
What is Vincent’s infection?
Acute ulcerative gingivitis involving the interdental papillae. Treat with metronidazole.
What investigations would you do for dysphagia?
If suspicious of motility disorder = Barium Swallow
If suspicious of mechanical = OGD
What 3 infections most commonly affect the mouth?
Herpes Simplex Virus Type 1
Coxsackie A
Herpes Zoster
What can cause candidiasis?
Broad spec antibiotics, ill fitting dentures, aspirin, immunocompromised
What can predispose you to GORD?
Increased abdominal pressure (pregnancy) Low LOS pressure Delayed gastric emptying Hiatus hernia Obesity Systemic Sclerosis TCAs
When is OGD required in pts with GORD?
New onset over 55 yo
Pts with alarm symptoms (w/l, dysphagia,anaemia)
What would you do if patient does not respond to antacids?
24h pH intra-luminal monitoring
How do you manage GORD?
Diet and Lifestyle advice
Antacids (alginate, magnesium, aluminium)
PPIs (omeprazole, lansoprazole) - inhibit H/K/ATPase
H2-Receptor antagonists (ranitidine, cimetidine)
Surgery
In oesophageal spasm, what do you see on Barium swallow?
Cork-screw appearance
What causes Hiatus Hernia?
Sliding (95%) - gastro-oesophageal junction slides up
Para-oesophageal hernias - gastric fundus rolls up through the hiatus alongside the oesophagus
What is a common compliciation of long-standing GORD?
Stricture formation (treat with balloon dilatation)
What is the pathological change in Barrett’s Oesophagus?
Dysplasia - Squamous epithelium becomes columnar
What is the risk of Barrett’s?
Developing adenocarcinoma (NOT squamous)
What protocol is followed if dysplasia is found on endoscopy?
Low-grade = repeat endoscopy in 6months + high-dose PPIs
High-grade = repeat 3 monthly with high-dose PPIs if no visible lesion. If visible nodular lesions, then endoscopic resection for histopathological staging.
Radio-frequency ablation is the preferred method of endoscopic treatment.
What causes achalasia?
Impaired relaxation of the lower oesophageal sphincter
LOS pressure is elevated in >50% of cases
How do you treat achalasia?
Endoscopic balloon dilatation
Heller’s cardiomyotomy
Where in the oesophagus are adenocarcinomas more likely to be found?
Lower 1/3 + cardia
Squamous most likely in the middle 1/3
What investigations for oesophageal tumour?
OGD and tumour biopsy
+/- Barium swallow
Staging is via CT scan
Treat with resection
What stimulates acid secretion in the stomach?
Histamine working on the parietal cells
Parietal cells also release intrinsic factor
What causes the release of Histamine?
Acetylcholine and Gastrin via the enterochromaffin cells
Therefore ACh, Gastrin and Histamine cause release of Intrinsic factor
What inhibits histamine and gastrin release?
Somatostatin (so this stops acid production)
What is the function of intrinsic factor?
Absorbs vitamin B12 in terminal ileum
What are the functions of the stomach?
Reservoir for food
Emulsification of fat + mixing gastric contents
Secretion of intrinsic factor
Absorption
What is H.Pylori?
Gram -ve spiral shaped bacteria
How do you diagnose H.Pylori?
Breath test (C-Urea) - also used to see if infection eradicated after treatment Stool antigen
Antral biopsy - Rapid urease CLO test (INVASIVE)
What are the complications of H.Pylori?
Chronic gastritis
Peptic ulcer disease
Gastric B cell lymphoma
Gastric cancer
How do you treat H.Pylori?
PPI-Triple therapy - all twice a day for 14 days
Omeprazole (20mg) + Metronidazole (400mg) + Clarithromycin (500mg)
Omeprazole + Amoxicillin (1g) + Clarithromycin
Why do NSAIDs cause ulcers?
Reduced PG production via blocking COX-1 which usually gives mucosal protection
What relationship to food do peptic ulcers have?
Duodenal cause symptoms when pt is hungry and typically at night
Gastric usually cause symptoms after eating
Epigastric pain, relieved by antacids, nausea, heartburn, flatulence
What investigations for ulcer-type symptoms?
Pts < 55 = non-invasive H.Pylori testing (stool, breath)
Pts > 55 or alarm symptoms/signs (W/L, dysphagia, vomitting, GI bleed, epigastric mass)
If pt undergoes endoscopy, then biopsy needed to distinguish between malignant and benign
How do you manage peptic ulcers?
Eradicate H.Pylori with triple therapy (if thats the cause)
If non H.Pylori, then give PPIs and stop any NSAIDs/aspirin until ulcer is gone, then can start again WITH PPI if needed. If not possible to stop, switch to COX-2 inhibitor.
Follow-up endoscopy plus biopsy is done for all Gastric ulcers to exclude malignancy
What are the causes of peptic ulcer disease?
NSAIDs, H.Pylori, Steroids, Aspirin
What are the complications of ulcers?
Perforation
Gastric outlet obstruction
Haemorrhage
What is Curling’s ulcer?
Ulcer caused by a burn in the stomach
What are RFs for gastric cancer?
H.Pylori, chronic gastritis, tobacco smoking, high salt diet, pernicious anaemia
Where do gastric cancers most commonly occur?
Antrum of the stomach (usually adenocarcinoma)
What investigations would you perform in suspected gastric cancer?
Gastroscopy + biopsy is initial investigation of choice
CT, EUS and laparoscopy then used to stage the tumour
What other types of gastric tumours are there (other than adenocarcinoma) ?
GISTs
Gastric lymphoma
What are common causes of upper GI bleeding?
Peptic Ulcers Mallory-Weis syndrome Gastric varices Reflux Oesophagitis Drugs - NSAIDs / Alcohol
How do you assess risk in a patient with GI bleed?
Rockall score
Looks at Age, BP + Pulse, Co-morbidities, Endoscopic stigmata, Diagnosis
What is pre-endoscopy drug therapy in a pt with upper GI bleed?
Stop aspirin, Warfirin, NSAIDS
Speak to cardiology regarding clopidogrel and aspirin
Reverse INR if severe enough
Give high-dose PPI if high-risk
What is a Mallory-Weiss tear?
Tear of the mucosa at oesophagogastric junction
History of vomiting preceding haematemesis suggests this pathology
What is the management of an upper GI bleed?
Resuscitation Assess risk (Rockall score) Pre-endoscopy drug therapy Endoscopy Treat based on cause (endoscopic haemostasis, surgery)
What antigens are associated with coeliac disease?
HLA DQ2 and HLA DQ8
What are the typical histological features of coeliac disease?
Villous atrophy
Crypt hyperplasia
Chronic inflammatory markers
What investigations would you perform in coeliac disease?
Serum antibodies - tTG antibodies and EMA antibodies (less specific)
Distal duodenal biopsy - for definitive diagnosis
FBC - anaemia is seen in 50% cases
DXA - due to increased risk of osteoporosis
Which part of gluten causes the problems seen in coeliac disease?
Alpha-gliadin
What is the management of coeliac disease?
Life-long gluten free diet Pneumococcal vaccine (coeliac associated with hyposplenism)
What are the complications of coeliac disease?
T-Cell lymphoma
Which individuals should be tested for coeliac?
Autoimmune disease - T1DM, Thyroid, Addison’s
IBS
Unexplained osteoporosis
Down’s and Turner’s syndrome
What is dermatitis herpetiformis?
Linked to coeliac disease
Itchy, symmetrical eruptions of vesicles on extensor surfaces due to IgA
Pts have gluten sensitivity, so gluten-free diet
What is tropical sprue?
Diarrhoea, steatorrhoea and megaloblastic anaemia
Pt has been to a tropical area
Small bowel mucosal biopsy shows similar features to coeliac
Treat with folic acid and tetracycline
What is a complication of bowel resection?
Small bowel syndrome - require parenteral nutrition
TB of the small intestine most commonly affects…
Ileocaecal valve
What is Whipple’s disease?
Rare, bacterial infection caused by Tropheryma whipplei
Abdo pain, fever, steatorrhoea, lymphadenopathy, arthritis
Treat with co-trimoxazole
What are carcinoid tumours?
Arise from enterochromaffin cells which are seretonin producing
Symptoms are therefore due to raised 5-hydroxytryptamine
Symptoms from GI carcinoid tumours only arise if mets to the liver, as 5-HT drains into hepatic vein without being metabolised by liver
Flushing, wheezing, diarrhoea, abdo pain
Blood will show high levels of 5-HIAA
Treat with somatostatin analogue - cyproheptadine (inhibits seretonin)
Surgical resection
What is Peutz-Jeghers syndrome?
Autosomal Dominant
Mucocutaneous pigmentation and GI polyps
What is the role of smoking cigarettes in IBD?
Protective in U.C, risky for Crohn’s
What are the macroscopic differences of Crohn’s and U.C?
Crohn’s - Any part of the GI tract, Oral and perianal disease, skip lesions, deep ulcers and fissures causing cobblestone appearance.
U.C - Affects only colon, begins in rectum and extends proximally, continuous involvement, red mucosa that bleeds easily
What are the microscopic differences of Crohn’s and U.C?
Crohn’s - Transmural inflammation and granulomas present
U.C - Mucosal inflammation, no granulomata, goblet cell depletion, crypt abscesses
What are the features of IBD?
Diarrhoea, abdominal pain, pain on defecation, w/l
Bloody diarrhoea with mucus often seen in U.C
Systemic features seen in relapse of U.C
What are the extra-intestinal manifestation of IBD?
Clubbing
Eyes - Uveitis, conjunctivitis
Joints - Arthralgia, arthritis, ank spond
Skin - Erythema nodosum, Pyoderma gangrenosum
Liver - Fatty liver, hepatitis, cirrhosis, sclerosing cholangitis
Kidney - stones
DVT
What investigations would you order for IBD?
Bloods, Cultures - blood + stool,
Flexible sigmoidoscopy +/- rectal biopsy
Colonoscopy
Small bowel imaging - barium follow through or video capsule endoscopy
What investigation would you do urgently if a patient came in with acute severe colitis?
Plain abdominal X-Ray - identifies toxic dilation of colon
What is the medical management of Crohn’s?
Steroids for moderate/severe disease
5-ASA more useful in U.C but occasionally used
Azathioprine to maintain remission in pts with regular relapses
Metronidazole in severe perianal disease
Anti-TNF antibodies are used for pts resistant to steroids
What is the medical management of U.C?
Aim to induce a remission
Mild = Prednisolone 40mg + Mesalazine Moderate = Prednisolone + 5-ASA (sulfasalazine, mesalazine) Severe = admit
Remember to taper steroids
Azathioprine is reserved for those who relapse often (>2 courses of steroids in a year)
Anti-TNF antibodies are used for pts resistant to steroids
Infliximab, Adalimubab
What is the management of severe colitis (after admission) ?
Blood and stool cultures x 3, AXR, Bloods
Nil by Mouth, IV fluids + correct electrolyte imbalances
Hydrocortisone IV 100mg 6 QDS
LMWH
If improves after 5 days, switch to oral prednisolone and 5-ASA. If not then give IV ciclosporin.
Close monitoring (vital signs QDS at least)
What is the management of severe colitis (after admission) ?
Blood and stool cultures x 3, AXR, Bloods
Nil by Mouth, IV fluids + correct electrolyte imbalances
Hydrocortisone IV 100mg 6 QDS
LMWH
If improves after 5 days, switch to oral prednisolone and 5-ASA. If not then give IV ciclosporin.
Close monitoring (vital signs QDS at least, stool charts)
When would surgical intervention (colectomy) be needed for UC?
Perforation Massive haemorrhage Toxic dilatation Failure to response to medical management Failure to grow (in children)
What are the complications of IBD?
Stricture formation Toxic dilation of colon +/- perforation Abscess formation Fistulae and Fissures Colon cancer
What are the rare side-effects of 5-ASA (sulfasalzine) ?
Steven-Johnson syndrome
Acute pancreatitis
What are the potential side-effects of Azathioprine?
Bone marrow suppression
Acute pancreatitis
What are the alarm symptoms associated with constipation?
Sensation of incomplete evacuation
Rectal bleeding
Recent onset in over 50s
How do you diagnose and treat Diverticulitis?
Diagnosed via CT scan
Treat with abx - Metronidazole and a Cephalosporin)
The risk of a polyp turning malignant increases with:
Size > 1cm Number Sessile (worse) vs Pedunctulated Level of dysplasia Villous histology (worse) vs Tubular
What are the familial colon cancer syndromes?
HNPCC - over 50% develop cancer
FAP - APC Gene - 100% risk of developing cancer
Multiple polyps form during teenage years
More associated with carcinoid syndrome
Peutz-Jeghers syndrome - STK11 gene - pigmented spots on lips and buccal mucosa
What is the oncogene involved in colorectal cancer?
K-Ras
What tumour marker would you ask for in CRC?
Carcinoembryonic antigen (CEA)
What investigations would you perform in suspected CRC?
Colonic examination - colonoscopy + biopsy is gold-standard
Bloods
CT (abdomen, chest, pelvis) scan to stage
What are the treatments for CRC?
Tumour resection +/- end-to-end anastamosis of bowel +/- colostomy
Post-op Chemotherapy
What is the screening program for CRC?
All individuals between 60-74 are invited for faecal occult blood tests (FOB) every 2 years. If positive, then colonoscopy.
High-risk individuals are screened using colonoscopy prior to the age of 45 (first-degree relatives with colon cancer or those from families with family colon cancer syndromes)
What is the difference between osmotic and secretory diarrhoea?
Osmotic - hypertonic substances in the bowel lumen draw fluid into the intestine. Stops when patient fasts.
Secretory - active intestinal secretion of fluids and electrolytes. Continues when patient fasts.
What are the causes of Osmotic diarrhoea?
Ingestion of non-absorbable substance (a laxative)
Generalised or a specific malabsorption defect
What are the causes of secretory diarrhoea?
Enterotoxins
Hormone-secreting tumours
Bile salts
Fatty acids
What is organic vs functional diarrhoea?
Organic is higher stool weights where as functional is usually increased frequency of stools but smaller volumes.
What points towards an organic cause of diarrhoea?
Large volumes, nocturnal diarrhoea, bloody stools, weight loss, steatorrhoea
How would you investigate chronic diarrhoea? ( >14days)
Stool cultures
Baseline bloods - FBC, ESR, coeliac serology,
If watery +/- blood = colonoscopy
If steatorrhoea / abnormal bloods = SBFT or OGD or CT
What symptoms suggest a functional GI disorder?
Nausea alone Vomiting alone Belching Post-prandial fullness Abdominal bloating Chest pain unrelated to exercise Urgency first thing in the morning
How to treat functional oesophageal disorders?
Amitryptalline or Citalopram
How to treat functional dyspepsia?
Reassurance and lifestyle changes
How to investigate IBS?
If young, check for coeliac and IBD
If old, colonoscopy and further investigations
Name some causes of intestinal obstruction
Adhesions Hernia's Crohn's disease Intussusception Carcinoma Diverticular disease Volvulus
What are the signs of peritonitis?
Tender abdomen
Guarding
Rigid abdomen
Absent bowel sounds IF generalised peritonitis
What causes appendicitis?
A faecolith that obstructs the lumen of the appendix
What are the feature of appendicitis?
Central abdominal pain, then localises to RIF
Anorexia
D+V
Pyrexia
Tenderness and guarding in RIF (localised peritonitis)
Rovsing’s sign - LIF hurts when you press RIF
What investigations would you order for suspected appendicitis?
WCC, CRP, ESR are raised
USS may show inflammation and mass
CT is highly sensitive and specific but only used if diagnosis in unclear
What is the management of appendicitis?
IV Fluids and Abx (Met + Cef)
Surgery
What defect results in generalised peritonitis?
Rupture of an abdominal viscus results in generalised tenderness over the abdomen as opposed to localised peritonitis.
Pt is shocked, lies still. Check amylase and CXR.
Eg. peforated ulcer, perforated appendix
What are the 2 types of intestinal obstruction?
Mechanical - dilated bowel above the obstruction. Colicky abdominal pain, vommiting, absolute consitpation, tinkling bowel sounds,
Small bowel = conservative, large bowel = surgical
Functional - paralytic ileus associated with post-op, opiate treatments. Pain often not present and bowel sounds only reduced. Gas is seen throughout bowel in AXR.
Name some methods of enteral nutrition
Oral
NG Tube - short term
PEG - those who need for more than 2 weeks
Percutaenous Jejunostomy
When do patients need nutritional support?
BMI < 15 = Severely malnourished
BMI 15-19 = If they are unlikely to eat for next 3-5 days due to their condition
BMI normal = If not expected to eat for next 7-10 days
What are the complications of Total Parenteral Nutrition?
Catheter related - sepsis, thrombosis, embolism, pneumothorax
Metabolic - hyperglycaemia, hypercalcaemia
Electrolyte disturbance
Liver dysfunction
How is TPN given?
Catheter - can be central vein or peripheral, only ever used for nutrition, not for drugs
What is refeeding syndrome?
Can occur within the first few days of refeeding by oral/enteral or parenteral route
Hypophosphatemia, Hypomagnesaemia, Hypokalaemia
Thiamine deficiency
Muscle weakness, rhabdomyolysis, cardiac failure, coma, hallucinations, fits
RFs are anorexia nervosa, alcoholics, rapid weight loss - even if obese.
Treat with Pabrinex (Vitamin supplements) + Feeding + correct electrolyte imbalances
How does Orlistat work?
Used in obesity occasionally
Inhibits pancreatic lipase
When is surgery offered for obesity?
Morbidly obese (BMI > 40) Severely obese (BMI > 35) with many complications due to obesity
Treat with Roux-en-Y or or Gastric banding
What are the types of antacids?
Aluminium Hydroxide - tend to cause constipation
Magnesium mixture - tend to be a laxative
Alginate-containing antacids (Gaviscon)
What are Ranitidine and Cimetidine?
H2-receptor antagonists
Reduce gastric acid secretions by blocking receptors
Used in GORD, Peptic ulcers, preventing NSAID gastric damage
What are the types of laxatives?
Bulk-forming - absorb water and increase faecal mass
Used in pts with colostomy, diverticular disease, IBS
Husk, Methylcellulose, Sterculia
Stimulants - increase colonic activity
Used for short term issues
Bisacodyl, Glycerol (Senna)
Osmotic - retain/attract water in the intestinal lumen
Used in treating hepatic encephalopathy
Lactulose, Macrogol, Magnesium or Phophate salts
What is Loperamide?
Anti-motility agent
Used in UC, Infective diarrhoea,
What are most cases of Diarrhoea treated with?
Diarolyte which is an oral rehydration salt
What are the types of drugs used to treat nausea and vomiting?
Antihistamines - block H1 receptors - Cyclizine, Promethazine - used in motion sickness, drug induced vomiting, vertigo
Phenothiazines - Dopamine antagonists - Chlorpromazine - Used for neoplastic disease, radiation sickness, general anaesthetic
Domperidone and Metaclopromide - block dopamine receptors and inhibit dopaminergic stimulation of CRT - used in post-op N+V
5-HT3-receptor antagonists - Block 5-HT3 in the chemoreceptor therapy zone (CRT) in the 4th ventricle - Ondensatron - Used after chemotherapy
