bacterial infection
"Chest cold w/ post nasal drip for 3 weeks. Been on meds for 4/10 days, 875 mg horse pills. 
Pros: no sinus pressure, cough lessened, voice back, no chest rattling and can sleep through the night
Cons: HUGE pill, slow to resolve coughing
Side effects: gas cramps followed by diarrhea in the beginning (but tolerable, like various foods or excess protein does), makes me feel even more drained, frequent urination, mild lower cramps. 
Method: one mid morning after a meal but with food and water. No dairy. One late evening after supper with bread and water. I think the key for me  is a solid meal prior with no dairy, and bread helps. I think if it dissolves before the food, then that's where the gastric issues and nausea come from."