I read somewhere that cayenne pepper actually helps repair the ling of the colon. Of course, spicy foods aren't all made spicy with cayenne pepper, and the dose that's beneficial is probably much lower than what's found in most spicy dishes.
A lot of people say their BMs burn after a spicy meal - maybe he has something irritated in there that flares up when the meal causes that burning.
Lately I've noticed a little blood in my stool. I've been eating Indian food every day for lunch for the past month. Lately my stomach feels like it's burning (a spicy burn) a little after lunch, and I thought that maybe that it was the Indian food and that was also connected with my stool issues. I'm glad I found this--I think that's my problem. I went out and bought some new lunch food, so I'll wait a week or so and hopefully it goes away!