Hi. Thanks for your query. Noted your history and understood your concerns. Clindamycin is an antibiotic and hence kills most of the bacteria in the intestines hence causing imbalance of bacterial flora and disturbing the normal functioning. This in turn causes the change in consistency and color of stool. I would advise you the following in such a situation: Stop the medication and report to your Doctor to get another one. Add on pre and probiotics. Take banana, curds/yogurt and activated charcoal. Check the stool if required. Never take Clindamycin in future.