Lifestyle changes are recommended as decreasing the amount of fat in the diet, Also caffeine as well as foods containing milk sugar found in dairy products. They mention avoiding spicy foods and foods that lead to gas including carbonated beverages, caffeine, raw fruits and vegetables such as beans, cauliflower, broccoli and cabbage.

If a person with this problem takes over the counter nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen and naproxen (Aleve) talk to your doctor about switching to other types of pain relievers. These NSAIDS can worsen the diarrhea associated with collagenous colitis and Lymphocytic colitis.

I refer you to Mayo Clinic information. It's very comprehensive. The information does state that this problem can interfere with quality of life, but with proper treatment, the prognosis for most people is good and symptoms gradually resolve completely.