I have had black stools and black diarrhea since yesterday morning. I ve had 5-6 bouts of very liquid, black bowel movements and 2-3 episodes of small black stools. I haven t eaten other than a banana since Monday night because my stomach just doesn t feel good, like stomach flu. I have slight pain in the center of my abdomen, just below my breastbone. How long should I wait before I see my doc?