Question

Considering the classification of purgatives:
(A). Lactulose is used as osmotic purgative
(B). Bisacodyl is used as irritant purgative
(C). Poloxamer is used as osmotic purgative
(D). Ispaghula is used as bulk purgative
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (B) and (C) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

To easily remember laxative classes:
- Bulk-forming: Ispaghula/Psyllium (absorbs water and swells).
- Osmotic: Lactulose, Magnesium Sulfate (draws water into the lumen).
- Stimulant/Irritant: Bisacodyl, Castor oil (irritates the mucosa).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Purgatives (laxatives) are agents used to promote defecation and manage constipation or impaction in veterinary patients.
They are classified based on their mechanism of action: osmotic, irritant/stimulant, bulk-forming, or emollient/lubricant.

Step 2: Detailed Explanation:
Let us analyze each statement to determine its accuracy:
- Statement (A): Lactulose is a synthetic, non-absorbable disaccharide.
It remains in the intestinal lumen, drawing water into the bowel via osmosis, which softens the stool and stimulates peristalsis. Thus, it acts as an osmotic purgative, making statement (A) correct.
- Statement (B): Bisacodyl is a diphenylmethane derivative.
It acts directly on the colonic mucosa to stimulate sensory nerve endings, promoting peristalsis and fluid accumulation. Thus, it acts as an irritant or stimulant purgative, making statement (B) correct.
- Statement (C): Poloxamers (such as Poloxamer 188) are surfactants.
They act as stool softeners (emollients) by allowing water and lipids to penetrate the fecal mass, rather than acting as osmotic agents. Thus, statement (C) is incorrect.
- Statement (D): Ispaghula (psyllium hydrophilic mucilloid) is a natural fiber source.
It absorbs water in the gut, swelling to increase fecal bulk, which mechanically stimulates peristalsis. Thus, it acts as a bulk-forming purgative, making statement (D) correct.

Step 3: Final Answer:
The correct statements are (A), (B), and (D). This corresponds to option (A).