Hi Boy,
This is going to sound odd... but it could be just a bit of red pepper! Pepper skin does not digest very well, same with chillis and some stuff used in processed food. It can be very disconcerting when you see them in your poo etc..., but believe me it's not that uncommon.
Hope that helps!
Graham.
~~~ It is a poor heart, and a poorer age, that cannot accept the conditions of life with some heroic readiness. RLS. ~~~