I have for a long time been suffering from irregular acute bouts of digestive unpleasantries, which seem to crop up at random amidst otherwise normal BMs. The symptoms are usually all the same: gas, bloating, cramping, urgency, diarrhea, severe rectal irritation/burning, and inability to produce a good BM (wil have 4-5 or more very small liquid BMs over the course of a few hours, but be unable to get anything out). It will happen suddenly, get worse over the course of a few hours, then linger around for half a day or longer before beginning to clear up. Sometimes I am able to help it clear up faster with an enema, though in really severe cases it doesn't help, or makes things worse.
I've been really perplexed as to what is causing it, as most of the major foods I intake prior to an episode seem to be the same sorts of things I eat on a regular basis without problems. I'm wondering if maybe something smaller, often overlooked like an additive or preservative might be at fault. Recently I did discover one food in particular which always causes an episode: ham/canadian bacon, egg and cheese muffins/croissants (store-prepared, like from mcdonalds or a gas station). However all of the major ingredients in that, I can consume in larger quantities on their own in home cooked meals without issue. I have pork or pork products semi-regularly, never with an issue, 4 scrambled eggs I can digest fine, wheat/bread/pasta I have all the time, dairy I know can cause gas and some constipation if I have a lot of it, but never any cramps/diarrhea.
Other potential food triggers that I suspect but can't really prove include pizza, and some (but not all) instant noodle products (possibly ones containing shellfish).
Does anyone know what might cause symptoms like this, or what might be a triggering factor for me? It would make my life so much easier if I could figure it out and just eliminate whatever it is from my diet.