Can melatonin cause blood in stool?

Melatonin is generally considered safe for short-term use and is not commonly associated with gastrointestinal bleeding or blood in the stool. However, individual reactions to supplements can vary, and some people may experience side effects. If you notice blood in your stool, it's important to consult a healthcare professional to determine the cause, as it may indicate a more serious condition unrelated to melatonin.