I have a very sharp pain in my right lower rib while riding my bike (after about 50K) last Saturday (May 10, 2003.) and I have to stopped for about a minute to recover from the pain. and when I reach home I went to the "john" and I have a black stool, I kinda got worried, so after and hour I called my doctor, ask me to see him as soon as possible, hope nothing seriuos

I would have guessed you had aggravated a previously cracked rib or something, but I don't think that would cause the black stool. Good luck, hope it's nothing too serious.

Black stool usually means oxidized blood in the stool. That blood has travelled a long way in order to become "oxidized" so it usually means the source is the stomach (versus a hemmroid which is bright red blood)

The stomach is shaped like an S and it can S over to the left or right so some people with ulcers get pain under the right rib, as well as the middle abdomen or under the left rib. Have you been gobbling up alot of asprin, Advils, Alleves, etc. ? Not unusual for ulcers to act up during vigorous activity when the blood supply to the stomach is at it's lowest and the delicate balance of protective prostaglandins and good blood supply to keep the mucosa intact is off balance. (that's why smokers are more prone to ulcers) . Good to hear you are going to see your doc. Hope all turns out ok.