I wish I knew what caused this, but I too get awful stomach aches (kind of a severe burning sensation) about 1-2 hours after eating eggs and avocado. I can eat foods (baked goods and stuff) that have been cooked with eggs in them, but eating just plain eggs (scrambled eggs, omelets, etc) absolutely kills me. I've never been tested for any type of food allergy because I feel like I can avoid them fairly easily... though I went to a mexican restaurant a couple of days ago, ate guacamole and ended my night curled up in a ball because my stomach started hurting so badly. I don't think it's the fat content because I can eat other fatty foods without a problem. I wonder if there's some sort of enzyme in these foods that just don't agree with me... I don't think it's an allergy because I don't get any other allergy symptoms and I can tolerate foods that contain eggs. I also do get a little upset stomach if I eat bananas, though I don't love bananas so I don't eat them... but the couple times I've eaten them, I haven't felt great.
Anyway, not sure if this helps at all but it's good to know that I'm not the only one going through this! I'll continue to do some research and update if I find any other specific information.
