Terri -
I never took Asacol or 6mp -- I don't think they were around in the 70's, early 80's. CD in itself can cause a lot of fatigue. I think it is just the nature of the beast. The body is fighting, fighting, fighting and just wears out... I remember feeling so fatigued, but because I was on so much prednisone, cortenemas and hydrocortisone suppositories, I felt wired. The brain felt one way and the body felt another. Now, when I feel fatigued, I check my calendar and it is usually time for my B12 shot!
Maybe one of the others here can answer your question about how they felt on Asacol/6mp.