I ate at a local restaurant on Tuesday, and out of 6 of us in the group, three got really sick. I, being on antibiotics for a sinus infection, got milder symptoms. On Wednesday, I felt better, and on Thursday had an Angiogram. Friday, during the late night, I started having severe disentary. Should I go to the urgent care, or will the antibiotic I m on get me over this? I m on Azithromycin for a serious sinus infection. I ve been on it for about 45 days and have another 45 days to go.... (Because of repeated infections, I ve been antibiotics off and on several times this year.)