When I was between age 13-19 I played competive basketball and I also ran cross country. I often had diarreha after strenous games or long fast runs. I never thought much about it at the time. Its been a few years since I played basketball and I stopped running hard core but now, 9 years later I have started cycling and running. In the last 3 months I have been running hard and I noticed the diarreha is back. I looked it up on the internet and turns out it is very common among strenous athletes. Much more common in runners than cyclists.
Does anyone else experience this ?