I have had collagenous colitis for 8 years (celiac for 15). I had 3 months of flares this summer due mostly to high stress and being on low-dose Lisinopril (Ace II) for (new) chronic kidney disease, not blood pressure. I'm 70 and collecting diseases is not a good hobby. The flares tailed off a couple of weeks off the Lisinopril. I've never taken meds for the colitis (partly due to being sensitive to too many with microscopic colitis). I've kept a food journal for 15 years and figured out that I am sensitive to legumes, NSAIDs, gluten, and dairy. I've been low sugar/salt/processed foods for years. I have a high fiber diet; psyllium husk combines insoluble and soluble fiber that helps to bulk unformed stuff and feeds the (mostly friendly) bacteria. Stress has a big impact on GI problems so controlling that, getting enough sleep, exercise, diet, and finding things to look forward to every day is important.