dental abscess
"My dentist prescribed some amoxicillin after tooth extraction, supposedly to prevent infection. The diarrhea after 3 days was bad enough to stop taking this medicine.  Well, since no sign of infection was present or ever present and I needed to spend time outside of a bathroom anyway.  That 3-day love affair was it for me and Amoxicillin. 

Despite the literatures' claims that ALL antimicrobials cause diarrhea, this is the first one that actually caused it for me.  I think I'm going to claim an allergy to this one from now on."