I ve been sick for the past two weeks, symptoms include: fatigue , dizziness, congestion, runny nose, and a cough. I assumed this was the flu , however, after I began feeling better, a day or two later I developed symptoms of nausea, bloating and cramps, and diarrhea. The last two days I ve been passing black stool (diarrhea). I ve taken seven doses of Imodium in the last 36 hours with no symptom abatement other than some minor relief from bloating. The warning label says not to take if your stool is black. What does this mean, and should I be concerned?