I was prescribe the 5 day course by my doctor for a bad sinus inf...

I was prescribe the 5 day course by my doctor for a bad sinus infection, I took the first 2 pills with a meal and plenty of water on the first evening. By noon the next day I was having very, very bad diarrhea and cramps. They continued for several hours then by the evening the diarrhea was gone. I took the second day's pill with dinner again last night. I had a much better night with little fever or sweating that had made me so miserable the previous 3 days. When I woke I felt much better until the diarrhea kicked in again. I am afraid to get more than a few feet from the toilet because of the suddenness of the cramps. I don't know if I will take another dose or not I certainly feel better but I'm not sure my rectun is up to the stress of a third bout of diarrhea!