Gastroenterology

Question 1

Histology of Ulcerative Colitis

Answer 1

Superficial inflammation with chronic inflammatory cells infiltrating the laminate proprietary with crypt abscesses, with little involvement of the muscularis mucosa and with reduction of goblet cells.

Question 2

Imaging for Ulcerative Colitis

Answer 2

Barium enema/CT/MRI - loss of normal haustral pattern with shortening of the large intestine; bowel appears like a smooth tube (hosepipe appearance). Undermined ulcers and pseudo polyps may be seen. Stricture formation or carcinoma produces fixed areas of narrowing.

AXR - acute dilatation when present; bowel gas may outline mucosal ulceration.

During acute dilatation, barium enema may produce perforation.

Question 3

DDx of Ulcerative Colitis

Answer 3

Colon carcinoma (bloody diarrhoea)
Infective enteritis
Antibiotic-associated pseudomembranous colitis
Acute ischaemic colitis
Irritable bowel syndrome

Question 4

Medical management of Ulcerative Colitis

Answer 4

Oral 5-aminosalicyclic acid (5-ASA) compounds - induce remission in mild/moderate colitis

• sulfasalazine (5-ASA + sulfapyridine)
• mesalazine
• olsalazine

If 5-ASA ineffective or severe colitis, treat with steroids (oral; or rectal in proctitis), consider azathioprine for steroid-sparing

Short-term anti-TNF agent infliximab if refractory to 5-ASA and steroids

If severe colitis, admit for IV steroids and fluids

Taper treatment once remission is achieved

Question 5

Histology of Crohn’s Disease

Answer 5

Submucosal inflammation, less marked than in UC, and numerous fissures down to the sub mucosa with or without chronic granulation tissue.

Question 6

Imaging for Crohn’s Disease

Answer 6

Barium enema - rose thorn appearance of spikes of barium entering deep into the bowel wall if mucosal ulceration is deep; skip lesions; coarse cobblestone appearance of the mucosa; (later) fibrosis causing narrowing (string sign) with proximal dilatation

Small-bowel enema - mucosal ulceration, luminal narrowing or pooling of barium in irregular clumps at the site of an inflammatory mass

Contrast CT/MRI

Indium-labelled white cell scanning to localise active disease

Question 7

Complications of Crohn’s Disease

Answer 7

Fever
Anaemia
Weight loss
Hypoalbuminaemia
Fistulae
Peri-anal fissures
Sepsis

Question 8

Medical management of Crohn’s Disease

Answer 8

Aminosalicyclates and corticosteroids to induce remission.

Mesalazine suppositories can be used in localised rectal disease.

Budesonide that is formulated to be released in the terminal ileum and colon can be effective with fewer side-effects than conventional steroids.

Anti-TNF treatment with infliximab, adalimumab or certolizumab pegol are usually reserved for patients who do not enter remission with mesalazine or steroids.

Methotrexate or ciclosporin may be useful in refractory disease.

Correct nutritional deficiencies and electrolyte imbalances.

Antibiotics (ciprofloxacin and metronidazole) are widely used for the treatment of fistulas; azathioprine and anti-TNFs may also help.

Question 9

Causes of upper GI bleeding

Answer 9

Peptic ulcer
Gastric ulcer
Mallory-Weiss tear
Oesophagitis
Oesophageal ulcer
Oesophageal varices 
GI malignancy
(Concurrent NSAIDs/aspirin + SSRIs)

Question 10

Management of upper GI bleeding

Answer 10

Admit to hospital

Resuscitate if evidence of intravascular volume loss

Question 11

Management of variceal bleeding

Answer 11

Upper GI endoscopy within 24hrs (and as early as condition allows)
Local diathermy or injection of a sclerosis that may arrest bleeding

If bleeding continues/recurs, surgery may be necessary

PPIs reduce mortality, rebleeding and the need for surgical intervention
-IV bolus followed by continuous infusion of PPI should be considered in high-risk patients

Question 12

Causes of lower GI bleeding

Answer 12

Haemorrhoids
Fissure
Ulcerative colitis
Crohn’s disease
Ischaemic colitis
Rectal, colonic, and caecal carcinoma
Diverticular disease
Meckel’s diverticulum
Polyps
Endometriosis

Question 13

Vitamin B12 deficiency causes…

Answer 13

…megaloblastic anaemia

Question 14

Vitamin D/calcium deficiency causes…

Answer 14

…osteomalacia/rickets

Question 15

Vitamin B deficiency causes…

Answer 15

…glossitis and angular stomatitis

Question 16

Vitamin K deficiency causes…

Answer 16

…deficient coagulation

Question 17

Potassium deficiency causes…

Answer 17

…muscle pain, weakness, abnormalities of cardiac rhythm

Question 18

Investigations for coeliac disease

Answer 18

Anti-tissue transglutaminase and anti-endomysial antibodies

Duodenal biopsy

Question 19

Histology of coeliac disease

Answer 19

Villus atrophy

Question 20

Causes of malabsorption

Answer 20

Coeliac disease

Bile salt deficiency (carcinoma of head of pancreas /gallstones /primary biliary cirrhosis /bile duct stricture -> obstructive jaundice -> malabsorption of fat -> steatorrhoea)

Pancreatic enzyme deficiency (chronic pancreatitis /carcinoma of pancreatic ducts/ cystic fibrosis/ pancreatic calculi/ benign pancreatic cystadenoma)

Post-surgical (gastrectomy /gastroenterostomy /small bowel resection)

Crohn’s disease

Question 21

Investigations for malabsorption

Answer 21

Bloods - anaemia, low folate, low iron, low transferrin, hypoalbuminaemia, prolonged PT, hypocalcaemia, hypophosphataemia, hypomagnesaemia, raised alkaline phosphatase

Measure faecal fat excretion over 3-5 days

Small intestinal barium meal - flocculation and segmentation of barium as evidence of excess mucus secretion; widening of the small intestinal calibration and decreased distance between adjacent bowel loops, indicating thickening of the intestinal wall; detection of diverticula, fistulae or Crohn’s

Question 22

Most common pancreatic cancer type

Answer 22

Adenocarcinoma

Question 23

Imaging for pancreatic cancer

Answer 23

USS or CT may show the tumour

ERCP may comfort diagnosis and allows palliative stunting of obstructed common bile duct to relieve pruritis and jaundice

Question 24

Management of pancreatic cancer

Answer 24

Resection is the only curative treatment, but less than 10% of patients are suitable for surgery.

Adjuvant chemotherapy may be of benefit.

Question 25

Differential diagnoses for acute pancreatitis

Answer 25

Cholecystitis
Acute myocardial infarction
Dissecting aortic aneurysms
Mesenteric vascular occlusion
Intestinal perforation

Question 26

Investigations for acute pancreatitis

Answer 26

Bloods:
Serum amylase - usually very high (>1000u/ml) within 24h of onset, can fall rapidly.
Serum calcium may fall
Leukocytosis

AXR - may show gallstones; pancreatic calcification (indicating previous inflammation); distended loop of jejunum or transverse colon (if close to inflamed pancreas)

CT - exclude other pathology

Question 27

Management of acute pancreatitis

Answer 27

Pain relief

IV fluid to correct electrolyte imbalance and maintain circulating volume, whilst monitoring central venous pressure

Nutritional support - enteral/parenteral

Monitor blood glucose

Renal support with haemodialysis or haemofiltration may be required

Monitor SaO2 and give O2 if needed

If pancreatitis severe or causing organ dysfunction, manage in HDU/ICU

If extensive (>30%) or infected necrosis of pancreas, drainage is required

Question 28

Conditions associated with chronic pancreatitis

Answer 28

Cystic fibrosis
Haemochromatosis
Hyper parathyroid is

Question 29

Investigations for chronic pancreatitis

Answer 29

Serum amylase is unhelpful

Imaging can be helpful, but may be normal (early disease) or difficult to distinguish between an inflammatory or malignant mass (later disease)

Investigate for malabsorption and exocrine pancreatic function, diabetes mellitus, and obstructive jaundice, if relevant.

Question 30

Management of chronic pancreatitis

Answer 30

Treat pancreatic malabsorption with a low-fat diet, fat-soluble vitamins, calcium and pancreatic enzymes (e.g. Pancrex V, Creon)

Treat diabetes mellitus

Remove gallstones if present

Consider sphincterotomy or pancreatectomy if recurrent attacks

Completely avoid alcohol

Question 31

Management of acute cholecystitis

Answer 31

Bed rest, analgesia (pethidine) and antibiotics according to local protocol

Early laparoscopic cholecystectomy

Question 32

Charcot’s triad

Answer 32

Fever + jaundice + upper abdominal pain -> ascending cholangitis

Question 33

Investigations for gallstones

Answer 33

USS will reveal most stones; CT or MRI provide alternative imaging modalities

Question 34

Management of gallstones

Answer 34

Remove if causing symptoms.

If stones removed include pigment stones, investigate for haemolysis.

In elderly patients or if surgery is contraindicated, sphincterectomy via ERCP may release the stones if they are in the common bile duct.

Ursodeoxycholic acid may prevent formation of stones and dissolve radiolucent stones if they are <2cm in diameter and if the gallbladder is functioning