Lactose intolerance and Colon Surgery

About 9 years ago, my boyfriend's ulcerative coloitis resulted in a full colectomy.  He's now 30 years old and he's been in reasonably good health since I've know him (3 years), but lately he's been feeling nauseous, fatigued, having hot and cold flashes, but doesn't have a fever or any other cold/flu symptoms.  Plus, it's periodic; one day he's in bed, the next he's perfectly fine.  I suggested to him that it might be a dairy allergy, because it always seems to be around the time he has ice cream or cheese.  However, these are not lactose intolerance symptoms.

My question is: can lactose intolerance or food allergies affect adults without a colon differently than the rest of us?  Do these symptoms sound like they might be caused simply by a food "disagreeing" with him?