Lower GI

Question 1

how does volvulus affect different age groups

Answer 1

Children: small bowel
Elderly: sigmoid colon

Question 2

explain how diverticular disease occurs

Answer 2

high intraluminal pressure > herniation of bowel mucosa through weak points in the bowel wall

Question 3

what can cause acute colitis

Answer 3

infection
drug/toxin
chemo/radiotherapy

Question 4

What bacterium causes pseudomembranous colitis

Answer 4

C diff

Question 5

explain the aetiology behind pseudomembranous colitis

Answer 5

C diff is commensal in the gut, kept under control by other bacteria
Course of ANTIBIOTICS kills off other bacteria
C diff is unopposed > produces toxin > colitis

Question 6

What antibiotics trigger pseudomembranous colitis

Answer 6

3Cs
ciprofloxacin
clindamycin
cephalosporin

Question 7

hgow do you detect C diff toxin

Answer 7

toxin stool assay

Question 8

what are symptoms of pseudomembranous colitis

Answer 8

explosive watery diarrhoe

Question 9

How do you treat pseudomembranous colitis

Answer 9

STOP causative antibiotic

Metronidazole / vancomycin > fidaxomicin > daecal transplant

Question 10

What are causes of ischaemic collitis

Answer 10

occlusion (arterial/venous)
small vessel disease (DM, hypercholesteraemia, vasculitis)
low flow states (CCf, hhaemorrhage, shock)

Question 11

Explain Chron’s disease effect on GI tract

Answer 11

• entire GI tract, mouth to anus
• mainly around large bowel, terminal ileum
• skip lesions
• transmural inflammation
• non-caseating granulomas
• THICK WALL, narrow lumen
• COBBLESTONE mucosa

Question 12

Explain UC effect on GI tract

Answer 12

• ONLY affects rectum and colon (+ backwash ileitis)
• continuous lesions
• superficial ulcers, confined to mucosa
• bowel thickness in normal
• shallow ulcer
• regenerating mucosa forms pseudopolyps

Question 13

what is a polyp

Answer 13

protrusion from bowel wall

Question 14

what are three types of neoplastic polyps (i.e. can develiop into tumour)

Answer 14

Tubular adenoma

Vollpis adenoma

Question 15

What is mode of inheritance of FAP

Answer 15

AD

Question 16

Explain FAP

Answer 16

large numbers of adenomatous polyps by age of 25

will very likeluy develop cancer

Question 17

what is the gene responsible for FAP

Answer 17

APC tumour suppressor gene on 5q21

Question 18

How do you manage FAP

Answer 18

preventative panproctocolectomy

Question 19

WHat is Gardner’s syndrome

Answer 19

Same as FAP, with extraintestinal manifestations (oseoma, epidermoid cyst, desmoid tumour, dental caries)

Question 20

What is mode of inhritance of HNPCC

Answer 20

AD

Question 21

explain HNPCC

Answer 21

No polyps

but very high risk of developing calcer regardless

Question 22

what is the most common type of colorectal cancer

Answer 22

ADENOCARCINOMA

Question 23

what staging is used for colorectal adenocarc

Answer 23

Dukes /TNM

Question 24

what are symptoms of chron’s

Answer 24

intermittent diarrhoea, pain, fever

Question 25

what are symptoms of UC

Answer 25

bloody diarrhoea with mucous | crampy abdo pain relieved by defecation

Question 26

what other disease is UC associated wiht

Answer 26

PSC

Question 27

what is carcinoid syndrome

Answer 27

tumour of enterochromaffin cell origin produced 5-HT (serotonin)

Question 28

where is carcinoid syndrome tumours found

Answer 28

bowel | also lung, ovaries, testes

Question 29

what are symptoms of carcinoid

Answer 29

bronchoconstriction flushing diarrhoea

Question 30

what are symptoms of carcinoid crisis

Answer 30

``` life threatening vasodilation hypotension tachycardia bronchoconstriction hyperglucaemia ```

Question 31

what IX for carcinoid

Answer 31

24h urine 5-HIAA

Question 32

what MX for carcinoid

Answer 32

octreotide (somatostatin analogue)

Question 33

WHo do hamartomatous polyps occur in

Answer 33

children under 5

Question 34

what are sx of hamartomatous polyps

Answer 34

bleeding (in rectum)

Question 35

what syndrome are hamartomatous polyps seen in

Answer 35

Peutz-Jeghers syndrome

Question 36

Explain Peutz-Jeghers syndrome

Answer 36

multiple polyps mucocutaneous hyperpigmentation freckles around the mouth, palms, soles increased risk of intusseption and malignancy

Question 37

what antigen marker can be used to monitor colorectal cancer

Answer 37

CEA

Question 38

what staging can you use for colon cancer

Answer 38

Dukes