bacterial infection
"I had a gum infection that got so bad that my face swelled up and was red and hot to the touch.  My dentist put me on clindamycin 3 times a day (4 times a day for the first 2 days), this did clear up the infection (was on it for 2 weeks) then was able to have the surgery needed (had to wait for the infection to disappear first), then had to stay on it for 5 days after surgery to prevent infection. I had to stop after 4 days, my heartburn and indigestion was so bad and have had black stools for past three days, going to wait to see if everything clears up after stopping medication. I haven't taken it since yesterday morning, I haven't had heartburn since yesterday afternoon."