Although studies have shown budesonide to be effective, not every patient with a histologic diagnosis of microscopic colitis needs it. It is reasonable to try antidiarrheal agents, bismuth, or both as a first step because they are inexpensive and have few side effects. If budesonide is used, it should be given for 6 to 8 weeks, then stopped, and the patient should then be monitored for symptom recurrence. If a flare does occur, budesonide can be restarted and continued as maintenance therapy.
Microscopic colitis is diagnosed histologically, while irritable bowel syndrome is a clinical diagnosis. In population-based cohorts of histologically confirmed microscopic colitis, 50% to 70% met symptom-based Rome criteria for the diagnosis of irritable bowel syndrome. The clinical symptom-based criteria for irritable bowel syndrome are not specific enough to rule out the diagnosis of microscopic colitis. Therefore, patients with suspected diarrhea-predominant irritable bowel syndrome should undergo colonoscopy with biopsy to investigate microscopic colitis if symptoms are not well controlled by antidiarrheal therapy. 26 The patient’s management may be very different depending on whether colonoscopy is done.
Management of microscopic colitis should include stopping any drugs associated with it. Simple antidiarrheal agents should be tried first to manage symptoms. If symptoms persist, patients can be treated with budesonide (Entocort EC) 9 mg by mouth daily for 8 weeks to induce remission, or 6 mg by mouth daily for 3 months as maintenance therapy.
OUR PATIENT’S COURSE
Our patient’s medication list includes duloxetine, a serotonin-norepinephrine reuptake inhibitor related to drugs that have been associated with the development of microscopic colitis. We tapered the duloxetine, and her symptoms improved by 50%. Her symptoms were eventually controlled after an 8-week course of oral budesonide 9 mg and ongoing intermittent use of loperamide (Imodium).