What are some natural remedies for slight mild ulcerative colitis flareups limited to rectum. I'm on asacol (mesalamine) hd 800 2t po tid?

Probiotics. First, are you sure you have uc? You may have underlying food allergies triggering this as well. Use the a4m.Com "doc locator" function to find a local functional medicine physician to do further GI testing to evaluate. In the interim i suggest higher dose probiotics like "probiotic 225" from orthomolecular 1 pack daily for flares and florajen 1 daily for regular support and to prevent flares.