Does he have any other symptoms besides bloody stool? There are a number of things that can cause it, but my favorites are the ones that promptly disappear as mysteriously as they appeared. If it persists and you believe that the blood is coming from inside then it’s probably time to schedule a GI appointment. If it’s not from hemorrhoids then other reasonably common possibilities include cuffitis and ulceration. If it’s a tiny amount it can be from skin irritation.

Definitely schedule an appointment ASAP! Did he take NSAIDS???

Please do not panic.

This happens and may be nothing, as Scott noted. It could also be cuffitis or pouchitis. But, the main thing is to observe your son. If he is not dizzy or weak, and not experiencing other symptoms, it is fine to wait a few days to call the doctor if it persists.

Jan