Hi,
As a Human suffering from the same kind of problem, I can probably put it into some kind of order for you.
Colitus, Diveticulistus (sp) which I have, irritable bowel syndrome and there is another. All give similar symptoms and are all where different parts of the iintestine flair up . Stress is the main cause and I control mine by diet, the daft thing is I can eat spicy curries but cant eat beef burgers but for me fruit and veg are great (so tell that to the cat). I do have to have tablets occasionaly . but if I get stressed my stomach everything goes into spasms and its not nice. So basically find out what he can eat, it may not be the most expensive, or best health food just what he can eat, and try and keep him calm. The first problem is the worst and once you know just watch out for it. It is not life threatening but I can tell you it is very painful. he may not have another problem with this again but again he may, but he will be fine.
luv
She