Hi llonda and welcome to the boards! There are a few members on HW with lymphocytic or collagenous colitis, but you might get more responses if you post in the Crohn's or UC boards, since lymphocytic colitis is classified as an inflammatory bowel disease. From what I understand, this disease has a somewhat similar course to Crohn's or UC; meaning it is chronic, that you may have flare-ups at times, but will have remission other times. The 5-ASA drugs are a pretty standard treatment but there are a lot of people who have had success with lifestyle changes, like you mentioned. How have your symptoms responded to those changes? Do you notice a difference?
One thing that you might ask your physician about is starting probiotic therapy. Your gut is normally full of "good" bacteria that help combat overgrowth of "bad" bacteria, and an imbalance in the two can exacerbate symptoms. A lot of studies have shown that increasing the "good" bacteria with probiotic formulas - either via over-the-counter supplements or in certain foods like yogurt - can restore the normal gut flora and reduce intestinal discomfort. One probiotic in particular, VSL#3, has been shown to be pretty effective in treating symptoms of ulcerative colitis (i.e., reducing diarrhea and pain).
Other people have had success with fiber therapy; fiber increases stool bulk, which can help people with symptoms of diarrhea and/or constipation.
Many of the diarrhea-prone IBSers on this board have had some success with calcium supplements; one of our members, lnape, is the expert on the calcium.
If you look around on this board you will find a lot of helpful hints for controlling symptoms. I'd encourage you to talk to your doctor about some of these "remedies." Feel free to keep posting here, or check out the IBD boards. :)
Co-moderator - IBS Forum