A patient was on long term antibiotic therapy for peritonitis. During the course of treatment, he develops mucus diarrhea. Most likely cause of diarrhea is: September 2012

Ans. B i.e. Antibiotic associated diarrhea Antibiotic-associated diarrhea (AAD)It results from an imbalance in the colonic microbiota caused by antibiotic therapy.Microbiota alteration changes carbohydrate metabolism with decreased sho-chain fatty acid absorption and an osmotic diarrhea as a result.Another consequence of antibiotic therapy leading to diarrhea is overgrowth of potentially pathogenic organisms such as Clostridium difficile.It is defined as frequent loose and watery stools with no other complications.