Question

Which of the following causes melanosis coli?

• A. Senna
• B. Sorbitol
• C. Magnesium Sulphate
• D. Bisacodyl

Answer 1

The Correct Option is A

Step 1: Melanosis coli is the dark pigment deposition in colonic mucosa seen with long-term laxative abuse.

Step 2: The culprits are the anthranoid (anthraquinone) plant-derived stimulant laxatives, namely senna, aloe, and cascara sagrada.

Step 3: From the options, senna is the only anthranoid agent, so it is the cause; chronic use also carries a possible association with increased colonic cancer risk.

Step 4: Osmotic agents (sorbitol, magnesium sulphate) and the non-anthranoid stimulant bisacodyl do not produce this pigmentation.

\[\boxed{\text{Senna}}\]