Gastroenterology 3

Question 1

Fidamoxicin mechanism of action?

Answer 1

Bactericidal ! - inhibit RNA polymerase

Question 2

What organism species is a major protective constituent of faecal flora?

Answer 2

Bacteroides spp.

Question 3

Most common presentation of IgG4 disease?

Answer 3

sclerosing cholangitis

Question 4

Commonest adenoma and adenoma likely to cause malignancy?

Answer 4

Commonest adenoma = Tubular

Adenoma causing cancer = Villous

Question 5

What malignancy is associated with coeliac disease?

Answer 5

Lymphoproliferative malignancy

GI cancer

Question 6

Eosinophilic esophagitis treatment?

Answer 6

PPI for 8 weeks

Then liquid budesonide if not responsive to PPI

Question 7

Types of laxatives - Eg. and mechanism of action

Osmotic

Stimulant

Pro-secretory

5HT4 agonist

bile acid transporter inhibitors

Answer 7

Osmotic - Lactulose/ Polyethylene ( more superior)

Stimulant- Bisacodyl, glycerin = propagate colonic contractions

Pro-secretory -stimulate efflux of water/ions into intestinal lumen - helps with defecation

5HT4 - Fast excitatory potentials - induce mucosal secretion

Elobixibant - induce bile acid malabsorption in terminal ileum - retrograde flow in colon = mix with microbiota producing bile acids that induce colonic secretion

Question 8

Role of Faecal Calprotectin?

Answer 8

Diagnostic screening + relapse predictor + assess mucosal healing
(Inflammation specific, not disease specific)

Question 9

Hereditary diffuse gastric cancer + Lobular breast cancer - what mutation?

Answer 9

CDH1 = E-cadherin

Question 10

Gilbert syndrome mutation?

Answer 10

UDPG

UAT1A1

Question 11

H.pylori failed treatment - then what?

Answer 11

Levofloxacin based triple therapy ( Levofloxacin, PPI, Amoxicillin)

OR 
Quadruple triple ( Metronidazole, bismuth, PPI, Tetracycline)

Question 12

Severe Hep E - treatment?

Answer 12

Ribavarin

Question 13

Hereditary hemochromatosis - specific test and clue?

Answer 13

Transferrin saturation > 55%

Hepcidin deficiency

Question 14

Lactose malabsorption - how to test for it?

Answer 14

Lactose intolerance test
- oral lactose and check BGL : +ve if symptoms after oral lactose and BGL didn’t rise > 1 mmol

Hydrogen breath test ( sensitive and specific)
- Rise in breath hydrogen after lactose ingestion

Small bowel biopsy ( gold standard)
-differentiate primary and secondary Lactose malabsorption

Genetic test
-LCT-13910 polymorphism

Question 15

Cow milk allergy - how to differentiate IgE and non-IgE mediated?

Answer 15

IgE mediated - Symptoms start < 2 hours after drinking

Non-IgE - symptoms > 2 hours after drinking

Question 16

Esophagus dysphagia symptoms?

Cause of it?

Answer 16

Chest pain + Regurgitation + Water brash

Cause - Brainstem CVA/ Parkinson’s disease

Question 17

Oropharyngeal dysphagia symptoms?

Utility to invx it?

Answer 17

Aspiration pneumonia, choking while swallowing + weakness, voice disturbance

Video fluoroscopy - barium swallow

Question 18

Main pathway for paracetamol metabolism?

smaller pathways for paracetamol metabolism?

Answer 18

Main pathways
UDP-glucuronosyltransferases (UAT1A1) and Sulfotransferases (SULT1A1)
- conjugate PCM into glucorinide and sulfate - excreted in urine

Small pathways

• NAPQI metabolism by Glutathione
• Renal excretion unchanged

Question 19

What is key features of Ogilvie syndrome?

Answer 19

Painless abdominal distention - rapid = Large colon

Treatment
Fast + NGT - decompress
Endoscopic decompression is usually successful but colonic distention reoccurs

Rectal tube not useful esp. proximally

Question 20

Blatchford score usage does what?

Rockall score usage does what?

Answer 20

Blatchford score
Predicts who needs admission and therapy
-unlikely need admission/treatment if;
Urea < 6.5
Normal vital signs

Rockall score
Risk categorization before and after endoscopy
-hemodynamic instability + bleeding = scope within 12 hours
-hemodynamically stable = Scope within 24 hours

Question 21

After endoscopy successful for UGIB - what is the next step?

Answer 21

Bolus IV PPI and keep on infusion for 72 hours

No need 2nd check of endoscopy unless clinically bleeding

Question 22

ZES is associated with what genetic syndrome?
it secretes what hormone and it’s function?

How to test for ZES?

How to treat ZES?

Answer 22

MEN1

Gastrin

• increase Gastric motility and lower oesophageal sphincters
• Increase gastric acid and pepsinogen secretion
• increase gastric, duodenal, colonic mucosa growth to secrete more gastrin!

Give secretin stimulation test - if Gastrin rises > 200 = ZES

Tx - PPI and anti-histamine