Gas, Loose Stool, Cramps...still ... clindamycin the culprit???

The beginning of June I was prescribed Clindamycin for abscess tooth, took 23 of the 30 150mg pills. The bad tooth was removed and the abscess is not there. Ever since I took those pills I have yet to have myself 100% and I believe that is why. I have not had any antibiotics/meds since then and even still my insides are telling me they are not right. Some days I will feel fine some days not, when I am not it goes for usually 2-3 days. The onset starts with excessive gas, then cramping, irregular bowel movements sometimes 3 times a days, then sometimes none on and off like this. Usually after going poo I feel worse then better. I generally will feel bad for a few days and then gradually get better. My bm's have not been normal, usually loose/thin. My diet consists of raisin bran, yogurt in the morning, sandwich/pasta/meat for lunch/dinner. I was tested for C-Diff with a stool sample, said neg. I know something is up but the hospital and doc says there is nothing wrong.