Hello Welcome to HCM.. I thank you for posting your query here and I m definitely going to help you out.. I being a surgeon, we encounter so many such cases day in and day out.. I read your question completely and have understood it well enough.. I will analyze all your points and provide necessary explanation and treatment.. 1. You get diarrhea after masturbation.. As far as my clinical knowledge goes, I can say with certainty that diarrhea and masturbation are two different entities and there s no correlation between the two.. But, yes. Without neglecting your query, I can say that during or around masturbation there may be some things which causes diarrhea. Like, may be infection, some kind of spicy food. Etc.. You have to figure it out.. 2. And, you are right. Stress won t generally causes diarrhea.. 3. Next day you are fine.. Well, again.. I would like to tell you that this is not a co existant problem. Please, take care and see what exactly is causing you this discomfort. There are so many myths associated with masturbation and hence mentally you may be correlating this diarrhea to masturbation. Hope this helps you, in case you need any further assistance, please let me know. Take care. God bless.