bacterial infection
"I had constant nausea and mild diarrhea on it until I eliminated dairy products. Took more than 24 hours after the last serving, but both the nausea and the diarrhea went  away. I've also experienced fatigue, vertigo and a lot of trouble concentrating. Ugh. But it does seem to be doing the job. I'm taking it and another antibiotic for an infected surgical wound."