Lecture 13 Lower GI tract disease

Question 1

Name the parts of the large intestine

Answer 1

Ileum, Cecum, ascending colon, transverse colon and descending colon, rectum.

Question 2

Large intestine membranes

Answer 2

Mucosa -> submucosa -> taeniae coli

Question 3

Define appendicitis

Answer 3

Acute bacterial infection of the appendix caused by lumen obstruction

Question 4

What are clinical symptoms of appendicitis?

Answer 4

Pain, rebound tenderness, systemic symptoms

Question 5

Define pseudomembranous colitis

Answer 5

Acute inflammation of the colon presenting with the formation of plaque like fibrinous exudate (pseudomembranes) covering parts of mucosa

Question 6

What causes pseudomembranous colitis?

Answer 6

Toxin produced by overgrowth of C.diff, replacing normal intestinal flora

Question 7

Who is more likely to develop pseudomembranous colitis

Answer 7

patients treated with broad spectrum antibiotics

Question 8

What are symptoms of pseudomembranous colitis?

Answer 8

Fever and lower abdo tenderness

Question 9

How is pseudomembranous colitis treated?

Answer 9

Stopping antibiotics, hydration, specifical antibacteria therapy

Question 10

Define inflammatory bowel disease

Answer 10

Chronic inflammatory conditions of unknown aetiology affecting the gastrointestinal tract

Question 11

What is the pathogenesis of IBD?

Answer 11

Genetics, environment, constitutional susceptibility

Question 12

What are the two types of IBD?

Answer 12

Crohn’s disease and ulcerative colitis

Question 13

What is crohn’s disease?

Answer 13

Idiopathic IBD, affects any part of GIT from mouth to anus. Has skip lesions

Question 14

What are the percentages of the areas affected by crohns disease?

Answer 14

50% ileum and colon, 30% terminal ileum and 20% colon alone. Perianal skin involvement (75%)

Question 15

Pathology of Crohns disease?

Answer 15

Mucosal ulceration, fissures, Oedema of adjacent epithelium (cobblestone), pseudopolyp formation regen. Transmural inflam, non-caseating

Question 16

Complications of Crohns disease?

Answer 16

Anaemia, malabsorption, fistulas, extra-intestinal. ^risk of bowel carcinoma.

Question 17

Define colitis?

Answer 17

Disease affecting only colon, starts in rectum spreading proximally, continuous mucosal disease.

Question 18

Microscopy findings for ulcerative colitis?

Answer 18

Affects mucosa only above muscularis mucosae, cryptitis, crypt abscess, goblet cell depletion, pseudopolp formation regeneration

Question 19

What is pseudopolyp formation regeneration found in?

Answer 19

Crohn’s and ulcerative colitis

Question 20

Complications of ulcerative colitis

Answer 20

Anaemia, electrolyte loss, extra-interstinal disease, ^ carcinoma risk.

Question 21

What mimic IBD?

Answer 21

Ischaemic colitis, radiation colitis, Behcet’s disease, pouchitis, diversion colitis,

Question 22

What genetic factors can lead to colorectal carcinoma?

Answer 22

Familial adenomatous polyposis & lynch syndrome

Question 23

What dietary factors can lead to colorectal carcinoma?

Answer 23

Low, fibre, bile aerobes, red meat, lack of vits and antioxidants

Question 24

What is involved in the National Bowel Cancer Screening Programme?

Answer 24

60-75 years old, faecal occult blood test (FOBT) -> colonoscopy looking for polyps

Question 25

What is a polyp?

Answer 25

Projection above an epithelial surface

Question 26

Define adenoma

Answer 26

benign tumour of glandular epithelium

Question 27

What does the quantity and size of the polyps mean?

Answer 27

The more polyps -> ^ the risk. The larger the polyp -> ^ likely to be malignant

Question 28

Notes on familial adenomatous polyposis (FAP)

Answer 28

Autosomal dominant, chromosome 5, polyps from mid-teens onwards, Carcinoma inevitable (15 years). Needs genetic counselling.

Question 29

Which condition needs genetic counselling?

Answer 29

Familial adeonmatous polyposis

Question 30

What are the variants of familial adenomatous polyposis?

Answer 30

Gardner's and Turcot syndromes

Question 31

Define lynch syndrome

Answer 31

hereditary non-polyposis colorectal carcinoma

Question 32

Notes on lynch syndrome?

Answer 32

autosomal dominant, associated with CRCa (70-85%)

Question 33

What disease is microsatellite instability is linked to?

Answer 33

Lynch syndrome

Question 34

Define TEMS

Answer 34

transanal endoscopic microsurgery

Question 35

What is the staging of colorecatal carcinoma?

Answer 35

Dukes stage A (above muscle 95%survival) B into serosal fat (66%) C LN involved (33%)

Question 36

Define desmoplasic response

Answer 36

Growth of fibres or connective tissue.