GI: Colorectal Disease

Question 1

What is the role of the colon?

Answer 1

Absorption of water and electrolytes

Propulsion of the contents of the caecum into the anorectal region

Question 2

What is constipation?

Answer 2

Consistent difficulty defecating resulting in straining and passage of hard stools

Question 3

What can cause constipation?

Answer 3

Inadequate fibre intake
Diabetes
Hypothyroidism 
IBS
Calcium channel blockers + Antidepressants 
Intestinal obstruction

Question 4

What is faecal incontinence?

Answer 4

Recurrent uncontrolled passage of flatus and/or stool

Question 5

What are diverticula?

Answer 5

Pouches of mucosa which extend through weakened areas of the colonic muscular wall

Question 6

What is diverticulitis?

Answer 6

Inflammation of diverticula

Question 7

How does acute diverticulitis present?

Answer 7

Colicky left iliac fossa pain
Bloody diarrhoea
Fever
Raised CRP and white cells

Question 8

How is acute diverticulitis diagnosed?

Answer 8

CT scan

Question 9

How is acute diverticulitis treated?

Answer 9

Cephalosporin and metronidazole

Question 10

Which part of the colon is most susceptible to diverticular disease?

Answer 10

Sigmoid colon

Question 11

Which vessels supply blood to the colon?

Answer 11

Superior and inferior mesenteric arteries

Question 12

What is the main cause of ischaemic colitis?

Answer 12

An occlusion in the mesenteric arteries

Question 13

Who is at risk of ishaemic colitis?

Answer 13

The elderly
Women on the oral contraceptive pill
Patients with thrombophilia

Question 14

How does ischaemic colitis commonly present?

Answer 14

Abdominal pain and rectal bleeding

Question 15

What investigation is done for ischaemic colitis?

Answer 15

Sigmoidoscopy (as sigmoid colon is most commonly affected)

Question 16

Which organism causes antibiotic induced colitis? How does it do this?

Answer 16

C.Diff. Produces toxins A and B which attack epithelium

Question 17

Which organisms commonly cause infective colitis?

Answer 17

C.diff
Campylobacter
E.Coli

Question 18

What are the symptoms of infective colitis?

Answer 18

Diarrhoea (±blood)
Cramping pain
dehydration
weight loss

Question 19

What investigations would be done in a patient suspected of having infective colitis?

Answer 19

Stool culture
AXR
Sigmoidoscopy

Question 20

What is a polyp?

Answer 20

A protrusion of an epithelial surface

Question 21

What are the three types of polyp?

Answer 21

Pedunculated (stalks)
Serrated (from villous)
Flat

Question 22

What is an adenomatous polyp?

Answer 22

A benign epithelial tumour that produces glands

Question 23

What is familial adenomatous polyposis (FAP)?

Answer 23

A type of colorectal cancer caused by mutations in APC gene (tumour suppressor gene)

Question 24

What is hereditary non-polyposis colorectal cancer (HNPCC)?

Answer 24

Accelerated progression from adenoma to cancer due to mutations in DNA mismatch repair genes

Question 25

What physical signs indicate Peutz-Jeghers syndrome?

Answer 25

Pigmented spots on the lips and buccal mucosa

Question 26

Which side of the body are most colorectal carcinomas found?

Answer 26

Left hand side

Question 27

What are the symptoms of a colorectal carcinoma?

Answer 27

Rectal bleeding
Altered bowel habit
Colicky abdominal pain
Anorexia
Weight loss

Question 28

How do carcinomas of the caecum and ascending colon present?

Answer 28

Iron deficiency anaemia

Right iliac fossa mass

Question 29

How is a colorectal carcinoma diagnosed?

Answer 29

Colonoscopy + Biopsy

Question 30

What is the treatment for colorectal cancer?

Answer 30

Surgery