Most common organism responsible for, pseudomembranous colitis is:

Ans. is 'a' i.e., Clostridium difficile(Ref: Harrison, 19th/e, p. 1091, 1092 and 17th/e, p. 819, 820; Ananthanarayan, 9th/e, p. 265 and 8th/e, p. 263)* Pseudomembranous colitis is the advanced form of Clostridium difficile-associated disease (CDAD).* Pseudomembranous colitis is diagnosed by detection of one or both C difficile toxins in stool and by endoscopic observation of pseudo membranes or micro abscesses in patients who have diarrhea and have been given antibiotics.