Not a good topic, but a scary one. I am an avid runner. I run probably 5 times a week. Mostly 1 hour a day. I have noticed that after a run like this, sorry but I have to know if this happens to anyone else. I have to go to the bathroom. There is blood in the toilet. It doesn't look like it is in the stool, which is very watery. Just when I run for an hour. If I run shorter 1/2, seems to be fine. This only happens immediately after and not later. Does this happen just to me? Going to the Dr.
it could be rectal bleeding. have you seen a doctor? try to avoid spicy or oily food for now.