Occasional Cramping & Vomiting

Hello all! I've tried searching for this specific issue, but didn't see anything.

I've had UC for 7 years and am currently on Asacol. Thankfully I haven't had a flare up in about 4 years. Over the last 3 years, roughly every 3 - 4 months I have what I thought to be a mini flare. I get extremely bad stomach and intestinal cramps that gradually get worse (over 3ish hours), sustain very badly to the point I'm vomiting (6-8 hours), then subside over the course of a day.

When I asked my GI doc he said it couldn't possibly be my UC because flares don't just come and go in a day. He said it was most likely food poisoning. I'm pretty good about knowing what I ate and find it kind of hard to believe I get food poisoning every three months (and remarkably my husband eating the same meals doesn't).

I haven't been able to link it to any specific food, though it sometimes follows periods of more unhealthy eating (major holidays). And sometimes it seems to be linked to increased stress. But with both of these, it's not consistent.

Anyone experience something similar?

Thanks in advance.