Hello, This is Dr. Klarida Papaqako answering your question. I read very careful your concern. Diarrhea is one of the side effects of clindamicin use. Clindamycin causes Clostridium difficile associated diarrhea (CDAD) because it can alter the normal bacteria in the colon and encourage overgrowth of Clostridium difficile, a bacteria which causes inflammation of the colon (pseudomembranous colitis). If I was your caring doctor, I would stop you on clindamycin, and substitute it with another antibiotic who will work the same treating the problem for which you are using it, but who may not cause that side effect you are having (if you still need to use an antibiotic). If the diarrhea doesn t stop, after stopping the medicine you also need to do a stool sample. Tests of one or more stool samples often can determine whether C. difficile is present in your colon. Hope this helps, Take care.