Lower Gastrointestinal tract

Question 1

Function of large intestine and rectum

Answer 1

Part of the digestive tract.
Most of digestion and absorption already done by this stage.
Mainly absorbs water and electrolytes to form a solid stool.

Question 2

Acute Appendicitis

Answer 2

sudden onset inflammation of the appendix

Pathology – obstruction of appendiceal lumen by a fecalith, calculus, tumour or worms causing an increased intraluminal pressure and bacterial invasion

Question 3

Peritonitis: Localised vs Generalised

Answer 3

The peritoneum is the lining of the abdominal cavity and the lining of the organs within the abdominal cavity.
Peritonitis is inflammation of this cavity due to a variety of causes, most commonly infection.
In appendicitis the inflammed appendix on coming in contact with the abdominal wall causes localised peritonitis.

Question 4

Treatment of Acute Appendicitis

Answer 4

Surgical and/or antibiotics

Question 5

Anti-biotic Associated Colitis/ Pseudomembraneous Colitis

Answer 5

Acute inflammation of the Colon characterised by the formation of adherent inflammatory pseudomembranes overlying the sites of mucosal injury.
Classically caused by toxins produced by Clostridium difficile that has over grown after competing bowel organism were eliminated by broad spectrum antibiotics

Question 6

Pseudomembraneous Colitis treatment

Answer 6

Typically develops in patients treated with broad spectrum antibiotics
Fever and lower abdominal tenderness
Treatment-
Speak to microbiology! (stop current antibiotic usually and possibly introduce a new antibiotic)
Hydration
Specifical antibacterial therapy

Question 7

Inflammatory Bowel Disease

Answer 7

Chronic inflammatory conditions of unknown aetiology affecting the gastrointestinal tract
Two main forms of idiopathic IBD
Crohn’s disease
Ulcerative colitis

Question 8

Crohn’s disease

Answer 8

Affects from mouth to anus: particularly terminal ileum(30%), colon alone (20%) and ileum and colon (50%)
Skip lesions (not continuous), intervening uninvolved areas often perianal skin involvement (75%)
Transmural inflammation:
Active chronic inflammation
with non-caseating
epithelioid granulomas
Can have Fistula formation

Question 9

Complications of Crohn’s disease

Answer 9

Anaemia
Malabsorption: fat, vitamins A,D,E,K, bile salts
Fistulas 
Extra-intestinal: skin, eyes, joints)
Increased risk of bowel carcinoma
Bowel obstruction and perforation

Question 10

Ulcerative colitis

Answer 10

Colon only
Starts in rectum
	spreads proximally
Continuous disease 
	(No skip lesions)
Mucosal disease 
	(No transmural involvement)
May involve whole colon
	 also appendix

Question 11

Complications of ULcerative colitis

Answer 11

Anaemia: iron deficiency from blood loss
Electrolyte loss from diarrhoea
Extra-intestinal disease: skin, eyes, joints, bile ducts (PSC)
Increased risk of carcinoma: related to duration and severity of disease
Need for surveillance for dysplasia

Question 12

Neoplasia

Answer 12

Benign Polyps – adenomas
Malignant Adenocarcinoma (cancer)
Different stages and grades of adenocarcinoma affect prognosis and treatment

Question 13

Colorectal Carcinoma - Aetiology (risk factors)

Answer 13

Genetic factors
Familial Adenomatous Polyposis
Lynch syndrome (hereditary non-polyposis colorectal cancer)
Chronic inflammation
IBD: UC, Crohn’s
Dietary factors
low fibre
bile aerobes
red meat
lack of vitamins, antioxidants

Question 14

National Bowel Cancer Screening Programme

Answer 14

All population 60-75 years
Faecal Occult Blood Test (FOBT)
If positive, refer for colonoscopy
Look for polyps (adenomas) and carcinomas
Refer for definitive treatment

Question 15

Signs and Symptoms of Bowel Cancer

Answer 15

Depends on the site of the lesion
Altered bowel habit
Blood PR
Iron deficiency anaemia
Weight loss
Disease can be advanced at the time of the presentation