I always seem to get stomach spasms and gas and nausea after eating almost anything. I suspect it may be some sort of food intolerance, but sometimes when I'm unsure, I'd check if I feel any gas or if I can see my stomach contracting inwards. This isn't a very good test, as sometimes I've thought I had something (maybe a norovirus) that would put me at risk of being sick, but then I never was sick. I also sometimes check for a fever and swollen lymph nodes if I get really anxious. Normally with this suspected food tolerance I have, I feel a lot better when I'm hungry and my stomach is empty. I sometimes have to wait until I'm empty to see if I feel better. I can't remember a time when this hasn't made me feel better, probably because I haven't had the norovirus in at least 3 years.