Diarrhoea KumarClarke

Question 1

Describe secretory diarrhoea, including mechanisms and symptoms.

Answer 1

1. Secretory: Active intestinal secretion of fluid and electrolytes, and decreased absorption. Surfeit of electrolytes in bowel draws water into lumen, causing enterocytes to secrete when they should be absorbing.
   Generally indicates a defect in the L intestine. Most watery.

Question 2

Describe osmotic diarrhoea, mechanism and symptoms.

Answer 2

Malabsorption of e.g. monosaccharides and amino acids; these end up in the L intestine, where they cause water to be secreted due to osmotic gradient. Vol. of diarrhoea reduced by absorption of fluid ileum and colon. Stops when diet ceased or malabsorptive substance discontinued.

Question 3

Define inflammatory diarrhoea.

Answer 3

Mucosal destruction.
Loss of fluid and blood.
Defective absorption of fluid and electrolytes.

Question 4

Describe the following aspects of acute diarrhoea:

1. Clinical features
2. Investigations
3. Management

Answer 4

1. Fever, abdo pain, vomiting. Dehydration, especial risk for young and old.
2. Only necessary after 5-7 days. Sample exam for ova cysts parasites c.difficile toxin. If unfruitful, sigmoidoscopy, rectal biopsy.
3. ORS. Antidiarrhoeals (codeine phosphate, loperamide) for relief but may prolong infection.

Question 5

What is secretory diarrhoea?

Answer 5

Active secretion of fluid and electrolytes as well as decreased absorption (cf osmotic which is passive).
Continues when patients fast.

Question 6

Potential causes of secretory diarrhoea?

Answer 6

Enterotoxins
Hormone-secreting tumours
Bile salts in colon following ileal disease
Fatty acids in colon following ileal resection

Question 7

How to determine whether diarrhoea has:

1. Organic
2. Functional basis?

Answer 7

1. Large-volume watery stool, nocturnal diarrhoea, bloody stool, weight loss, steatorrhoea.
2. Frequent passage small volume.

[distal colon cancer & proctitis present with functional appearance despite being organic]

Question 8

What percentage of GI clinic visits are accounted for by functional complaints?

Answer 8

80%

Question 9

What is normal stool frequency?

Answer 9

3x a day to 3x a week.

Question 10

What is the definition (WHO) of diarrhoea?

Answer 10

3 or more watery or loose stools (taking shape of contained) in 24h.

Question 11

What is the point at which diarrhoea becomes chronic?

Answer 11

After 2 weeks of loose stools.