Hi Marilee -
I have trouble with food fiber while flaring, but I have taken fiber via Metamucil for years (like... 25 years.) My Gi had recommended it so I'd "never have o strain again" and .. that's true. Also it helps to add bulk to my stools, making them easier to pass.
There are a number of fiber products out there. My teeth don't meet that well to chew efficiently, so sometimes food fiber causes me discomfort.
If you start fiber, start with a small dose and plenty of water, then increase after a week or so.
I know it took me a while to get over the idea of "Having To Take Meds" but - other than that, the 5-ASA meds are pretty safe and are thought by some to decrease the long-term cancer risk of UC. So.... not so bad, eh?
My doc had told me that if I switched to the Asacol HD I'd be taking 4 a day, so... 3 isn't incredibly high. (But high enough to do some good!)
Some people lessen their dose when in remission... I leave it as it is.
Happy reading....!