L9 Laxative and Bowel Cleansing

Question 1

Definition of Constipation?

Acute vs. Chronic?

Answer 1

Infrequent/Fewer than 3 bowel movements per week

Reduced water in feces => hard, dry small feces w/ difficulty

Acute (<1week )
Chronic (>4weeks)

Question 2

Factors contributing to Fecal Dehydration?

Answer 2

Prolonged bowel transit time (allowing more absorption of water by the GI tract)

Reduced ability of stool to retain water (low fiber content)

Question 3

Primary vs. Secondary Constipation?

Answer 3

Primary Constipation:

• Dietary factors (insufficient fiber)
• Sedentary lifestyle
• Disorder of colonic propulsion or rectal emptying

Secondary Constipation

• Drug treatment (opioids, antihypertensive agents)
• Organic Diseases (Hypothyroidism, Parkinson’s)
• Local Pathology (colon cancer, diverticular stricture)

Question 4

What score would constipation get on the Bristol Chart?

Answer 4

Type 1/2

Question 5

Disease characterized by absence of ganglion cells in rectum/colon and inability to expel stools leading to constipation?

Treatment?

Answer 5

Hirschsprung’s Disease

Surgery to bypass or remove diseased part of colon

Question 6

Complications of Constipation?

____________(swollen, inflamed veins - caused by straining; may be associated with rectal bleeding)

____________ (small tears in the anus that may cause itching, pain, or bleeding)

____________(excessive straining during bowel movements, can require surgery in some cases)

____________ occurs when hard stool packs the intestine and rectum so tightly that the normal pushing action of the colon is not enough to expel the stool. Can become life threatening.

Answer 6

Hemorrhoids(swollen, inflamed veins - caused by straining; may be associated with rectal bleeding)

Anal fissures (small tears in the anus that may cause itching, pain, or bleeding)

Rectal prolapse (excessive straining during bowel movements, can require surgery in some cases)

Fecal impaction occurs when hard stool packs the intestine and rectum so tightly that the normal pushing action of the colon is not enough to expel the stool. Can become life threatening.

Question 7

Pharmacological Treatments of Constipation?

Answer 7

Bulk-forming agents (e.g. methylcellulose, bran)

Osmotic laxatives (e.g. Milk of Magnesia / Magnesium salts)

Stimulant / Irritant laxatives (e.g. Senna, bisacodyl, glycerol)

Stool softeners/emollients (e.g. arachis oil; docusate sodium; glycerol)

Question 8

_____________ is main nerve supply to GIT, stimulation of which leads to peristaltic reflex

Answer 8

Myenteric Plexus is main nerve supply to GIT, stimulation of which leads to peristaltic reflex

Question 9

FIRST LINE for simple constipation?

Answer 9

Stool-Bulking Laxatives (e.g. wheat bran; ispaghula; methylcellulose)

Question 10

Most commonly used osmotic laxative?

MOA?

What else does it do?

Answer 10

Lactulose

MOA: Synthetic dissacharide sugar broken down in Large intestine by bacteria into mild organic acids=> Draws water into colon

Acts as Colonic Acidifier- used to treat hepatic encephalopathy (high levels of ammonia in blood)

Question 11

Goal when managing constipation is to restore the amount of water in the faeces by:

1. ______________________________________
2. ______________________________________

Answer 11

Goal when managing constipation is to restore the amount of water in the faeces by:

1. Reducing bowel transit time
2. Increasing the ability of the feces to retain water

Question 12

Drugs used to treat abdominal pains and spasms in IBS?

Class 1 vs. Class 2?

Answer 12

Antispasmodic Agents

Class 1 (Dicycloverine, Propantheline, Hyoscine): Antimuscarinics block ACh transmission at nerve endings => smooth muscle relaxation

Class 2 (Alverine, Mebeverine, Peppermint Oil): Smooth muscle relaxants

Question 13

Anti-Foaming agent reduces bloating and discomfort caused by excess gas in GIT

Used for colic/wind pain, including in infants

Answer 13

Simethicone

Question 14

_________________________________________:

• Lower surface tension of bowel fluids
• Useful in management of anal fissure and hemorrhoids
• Often combined with other agents.

Answer 14

Stool softeners/emollients (e.g. arachis oil; docusate sodium; glycerol)

• Lower surface tension of bowel fluids
• Useful in management of anal fissure and hemorrhoids
• Often combined with other agents.

Question 15

____________________________________________:

• Help stools retain fluid, softens stool
• Can effect bacterial growth through pH change

Answer 15

Osmotic laxatives (e.g. Milk of Magnesia / Magnesium salts):

• Help stools retain fluid, softens stool
• Can effect bacterial growth through pH change

Question 16

_____________________________________________:

• Add bulk and retain water - making stools bulkier and triggering contractions.
• Increased viscosity can effect bacterial proliferation – these agents reduce viscosity

Answer 16

Bulk-forming agents (e.g. methylcellulose, bran):

• Add bulk and retain water - making stools bulkier and triggering contractions.
• Increased viscosity can effect bacterial proliferation – these agents reduce viscosity

*FIRST LINE for simple constipation**

Question 17

__________________________________________________:

• Stimulate myenteric nerves and motility
• Can cause “lethargic colon” if overused
• Contraindicated in intestinal/bowel obstruction

Answer 17

Stimulant / Irritant laxatives (e.g. Senna, bisacodyl, glycerol)

• Senna sides (Cleansing Teas) stimulate myenteric nerves and motility
• Can cause “lethargic colon” if overused
• Contraindicated in intestinal/bowel obstruction