UC pancolitis patients can have ileum-backwash, and that's not unusual. Backwash creates a small amount of inflammation in the ileum. I'd just verify that was ruled out.
You can get a small-bowel follow through, drink some contrasting dye and have imaging done to see if there's any small intestinal involvement.
You can get the relatively new prometheus labs ibd sgi blood test.
www.prometheuslabs.com/Resources/IBDDiagnostic/IBDsgi-ProductDetailDX13005-0113.pdfIn another post, you and I had talked about
Imuran in depth, so I won't bark up that tree again. I assume you find remicade to be equally extreme... I'd try not to eliminate multiple classes of IBD meds from your treatment path, as you might need them some day.