Had ulcer in colon/ terminal illeium after bad food poisoning episode. crohns suspected. redo colonscopy 1 year later, with no meds and colon was clean. had a 2nd opinion with ibd specialist and did a capsule endoscopy and that was clean. idea?

Sounds like your transient ulcer has resolved based on normal endoscopic studies. Are you still having some collection of symptoms? Or do you just want to know why you developed an ulcer?

Time will decide, in general inflammatory bowel diseases may relapse in decades intervals. So far with no evidence for inflammation would assign it to the acute condition.

If you do not have any intestinal symptoms, let the bygones be bygones. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines