I have Ulcerative Colitis. It is pancolitis (whole colon). I have had it 32 years. I take Coumadin blood thinner for a blood clot in my leg 2 years ago. I bleed a little more but not much. My personal care physician takes blood on me anyway every few months. I always remind him to order a test to make sure I am not anemic. I never am. Don't worry. None of my doctors do.
Ulcerative Colitis since about 1976
Pan colitis since at least 1994
30 years with UC and never had a flare until MD gave massive dose of Magnesiun while hospitalized for bronchitis. Then was hospitalized a few days for moderate flare. No flares since.