Clindamycin
"I was taking 300mg of Clindamycin 4 times a day for 7 days for a gum infection, after a day started having extremely loud intestinal rumbling, passing loud, long gas and severe diarrhea.  I cannot even pass gas without having to go to the bathroom and wipe myself or even urinate without having some diarrhea. Rectal/anal area is raw and painful from the diarrhea, my skin is itchy and have this weird taste in my mouth.  I've now finished the clindamycin and 4 days later, I still have the gas and loose stools. Can't wait until it's all over. It did work on my gum infection but the infection was nothing compared to the treatment."