Gastroenterology Lectures Flashcards
List 2 locations where Crohn’s disease is most prevalent.
1) terminal ileum
2) proximal colon
What is the characteristic inflammation of Crohn’s disease?
Skip lesions.
Define skip lesions.
Normal bowel mucosa in between diseased bowel mucosa.
Define transmural.
Occurring across the entire wall of a vessel/organ, e.g. in Crohn’s: mucosa, submucosa, muscle, serosa.
List 3 side effects of azathioprine.
1) bone marrow suppression
2) acute pancreatitis
3) allergic reaction
Where does ulcerative colitis affect?
Colon, never proximal to ileocaecal valve.
What is the characteristic inflammation in ulcerative colitis?
Circumferential and continuous.
What part of the colon wall does ulcerative colitis affect?
Mucosa.
What part of the colon wall does Crohn’s disease affect?
Transmural, i.e. mucosa, submucosa, muscle, serosa.
Define faecal calprotein.
Marker of bowel inflammation, i.e. non-specific marker of IBD.
Define toxic megacolon.
Acute colonic inflammation and distension.
Define short bowel syndrome.
Malabsorption due to lack of functional small intestine.
Define erythema nodosum.
Tender, red cutaneous nodules due to adipocyte inflammation.
Define pyoderma gangrenosum.
Deep leg tissue ulcers.
Define aphthous oral ulcers.
Recurrent round mouth ulcers.
Define refractory disease.
Disease that doesn’t respond to treatment.
Define colectomy.
Surgical removal of colon.
Define proctocolectomy.
Surgical removal of rectum and part/all of colon.
List 3 5-ASA aminosalicylates.
1) sulfasalazine
2) mesalazine
3) olsalazine
What is the function of 5-ASA aminosalicylates?
Anti-inflammatory drug used to treat inflammatory bowel disease.
List 2 commonly prescribed glucocorticoids.
1) prednisolone
2) hydrocortisone
List 2 immunosuppressive medications.
1) methotrexate
2) azathioprine
What is the difference between bloating and distension?
1) bloating is the sensation of abdominal swelling
2) distension is an increase of abdominal size
What percentage of the population have irritable bowel syndrome?
15%.
What mneumonic indicates irritable bowel syndrome? (3)
ABC
1) abdominal discomfort/pain
2) bloating/distension
3) change in stool form/frequency
What is a low FODMAP diet? (6)
A diet low in:
1) fermentable
2) oligosaccharides
3) disaccharides
4) monosaccharides
5) and
6) polyols
Define prolamin.
Group of plant storage proteins.
List 3 prolamins.
1) wheat - gliadin
2) barley - hordein
3) rye - secalin
List the 2 HLA groups found in coeliac disease.
1) HLA-DQ2 (95%)
2) HLA-DQ8 (5%)
Define crypt hyperplasia.
Elongated intestinal crypts, i.e. decreased villi/crypt ratio.
Define sliding hiatus hernia.
Stomach cardia extends through oesophagus hiatus in diaphragm.
Define rolling hiatus hernia.
Stomach fundus protrudes through oesophagus hiatus in diaphragm.
Define Barrett’s oesophagus.
Metaplasia of lower oesophageal squamous epithelium to columnar epithelium.
List 4 instances when an oesophagogastroduodenoscopy should be carried out on a suspected GORD patient.
1) alarm symptoms (dysphagia, haematemesis, weight loss)
2) 4 weeks of symptoms
3) symptoms despite PPI trial
4) over 55 years old
How common are oesophageal cancers?
6th most common worldwide.
Define achalasia.
Dysfunctional oesophageal peristalsis, failure of lower oesophageal sphincter to open during swallowing.
Where do oesophageal squamous cell carcinomas generally occur?
Upper 2/3 of oesophagus.
Where do oesophageal adenocarcinomas occur?
Lower 1/3 of oesophagus.
How much does your oesophageal cancer risk increase with previous reflux symptoms?
8x.
List 4 foods that decrease oesophageal cancer risk.
1) fibre
2) carrots
3) vitamin C (e.g. oranges)
4) folate (e.g. legumes)
List 4 foods that decrease gastric cancer risk.
1) non-starchy vegetables
2) fruit
3) garlic
4) low salt
Describe intestinal gastric adenocarcinomas. (5)
1) well differentiated
2) well formed
3) form polyps and ulcers
4) generally affect distal stomach
5) better prognosis than diffuse
Describe diffuse gastric adenocarcinomas. (5)
1) undifferentiated
2) poorly cohesive
3) infiltrate gastric wall
4) affect any part of stomach, esp. cardia
5) worse prognosis than intestinal
What size do polyps range between?
Few millimetres —> several centimetres.
Describe the genetics of familial adenomatous polyposis. (2)
1) autosomal dominant
2) mutation of APC gene
What is familial adenomatous polyposis characterised by?
Hundreds to thousands of colorectal and duodenal adenomas (polyps).
At what ages do adenomas and adenocarcinomas develop in familial adenomatous polyposis? (2)
1) adenomas - 16
2) adenocarcinomas - 39
Describe genetics of Lynch syndrome. (2)
1) autosomal dominant
2) hMSH1/hMSH2 gene mutation
What is Lynch syndrome also known as?
Hereditary non-polyposis colon cancer.
Describe what happens in Lynch syndrome.
1) hMSH1/hMSH2 mutation
2) decreased DNA stability in replication
3) increased DNA damage in replication
4) increased risk of colorectal adenocarcinoma development
How long do polyps take to develop into colorectal adenocarcinoma?
10-15 years.
How common are colorectal adenocarcinomas?
3rd most common cancer worldwide.
Where do the majority of colorectal adenocarcinoma occur?
Distal colon.
Where are gastric ulcers commonly found?
Lesser curvature of stomach.
Where are duodenal ulcers commonly found?
Duodenal cap.
What percent of the population have duodenal ulcers?
10%.
What is a more common peptic ulcer?
Duodenal ulcers are 2/3x more common than gastric ulcers.
What is the most common surgical emergency?
Acute appendicitis.
Define faecolith.
Hard faecal mass.
Define McBurney’s sign.
Right iliac fossa tenderness.
Define Rovsing’s sign.
Right iliac fossa pain when compressing left iliac fossa.
Define psoas sign.
Right iliac fossa pain when lying on left side.
Define obtrurator sign.
Right iliac fossa pain when right thigh is internally rotated.
Define fetor.
Strong foul breath.
Define tenesmus.
Cramping rectal pain.
Define volvulus.
Twist/rotation of a bowel segment.
Define paralytic ileus.
Adynamic bowel due to absence of peristaltic contractions.
What percentage of bowel obstructions occur in the small bowel?
75%
What percentage of bowel obstructions occur in the large bowel?
25%.
List differences between small bowel obstruction compared to large bowel obstruction. (6)
1) presentation is earlier in SBO
2) abdominal pain is higher in SBO
3) abdominal pain is more colicky in SBO
4) less abdominal distension in SBO
5) vomiting is earlier in SBO
6) constipation is later in SBO
List differences between large bowel obstruction compared to small bowel obstruction. (6)
1) presentation is later in LBO
2) abdominal pain is lower in LBO
3) abdominal pain is more constant in LBO
4) more abdominal distension in LBO
5) vomiting is later in LBO
6) constipation is earlier in LBO
Define diverticulum.
Bowel wall outpouching, mucosa herniates through colon smooth muscle.
Define diverticulosis.
Presence of diverticula.
Define diverticular disease.
Presence of symptomatic diverticula.
Define diverticulitis.
Inflammation of diverticulum
Where are diverticula generally found?
Entry sites of perforating bowel arteries.
When are diverticula generally found?
Incidentally during a colonoscopy.
What percentage of diverticula are asymptomatic?
95%.
Define Meckel’s diverticulum.
Usually asymptomatic congenital diverticulum in ileum.
What percentage of the population have a Meckel’s diverticulum?
2-3%.
What is acute inflammation of Meckel’s diverticulum clinically indistinguishable from?
Acute appendicitis.
Where is norovirus infective diarrhoea most common? (3)
1) cruise ships
2) hospitals
3) restaurants
What is the most common cause of bacterial diarrhoea?
Campylobacter jejuni.
What is the most common cause of diarrhoea in children?
Rotavirus.
What is the rule of C?
Antibiotics beginning with C can cause antibiotic induced Clostridium difficult diarrhoea.
What is the most common cause of travellers diarrhoea in Latin America?
E. coli (enterotoxigenic and enteroaggressive).
What is the most common cause of travellers diarrhoea in south east Asia?
Campylobacter jejuni.
List 5 causes of non-inflammatory watery diarrhoea.
1) enterotoxigenic Escherichia coli (ETEC)
2) Vibrio cholera
3) Rotavirus
4) Norovirus
5) Giardia
List 5 causes of inflammatory bloody/mucoid diarrhoea.
1) Campylobacter jejuni
2) enterohaemorrhagic Escherichia coli (EHEC)
3) enteroinvasive Escherichia coli (EIEC)
4) Shigella
5) Salmonella
Why are external haemorrhoids extremely painful?
They are close to a sensory nerve.
What age do haemorrhoids affect?
45-65 years old.
Define pruritus ani.
Itchy anus.
Define change in bowel habit.
Change in frequency or consistency of stools.
Define natal cleft.
Bum cheeks
Define skin maceration.
Softening and breakdown of skin due to chronic moisture exposure.
List 2 areas of the bowel that are most susceptible to bowel ischaemia.
1) splenic flexure
2) caecum
What is the most common type of bowel ischaemia?
Chronic colonic ischaemia.
What’s another name for chronic mesenteric ischaemia?
Intestinal angina.
What’s another name for chronic colonic ischaemia?
Ischaemic colitis.
List 2 things that indicate mesenteric ischaemia.
1) atrial fibrillation
2) abdominal pain
Define sitophobia.
Fear of eating.
What is the classical clinical triad of acute mesenteric ischaemia? (3)
1) severe acute abdominal pain
2) no/minimal abdominal signs
3) hypovolaemia
