Microscopic colitis: a review

What do we know today about drug-induced microscopic colitis? A case of lymphocytic colitis on olmesartan

Microscopic colitis is part of the differential diagnosis of chronic watery diarrhea. Colonoscopy discloses a normal looking mucosa, therefore its diagnosis is based on histology of colonic biopsies. Two main phenotypes are distinguished: collagenous colitis and lymphocytic colitis. A third entity, incomplete microscopic colitis or unspecified microscopic colitis has been reported in the literature. It affects preferentially women over 60 years of age and its association with certain drugs is increasingly established. In case of suspected drug-induced microscopic colitis, identification of the responsible drug is a key to management. After discontinuation of the suspected drug, the gold standard of treatment is budesonide both for induction and for maintenance in case of clinical relapse, as is often the case after discontinuation. Therapy with immunomodulators, biologics, or surgery is reserved for refractory forms of microscopic colitis after multidisciplinary consultation. Through the clinical case of colitis on olmesartan, we will review the latest recommendations on drug-induced microscopic colitis.

Lymphocytic colitis pattern of injury presenting as endoscopic polyps: a case series

Lymphocytic colitis (LC) is characterized by chronic watery diarrhea and unremarkable endoscopic findings. Only one case of LC presenting as multiple colonic polyps has been reported. We report a case series of histologic LC pattern of injury (LCPI), presenting as endoscopic polyps, and compare them with typical LC cases. Eighteen archived (2009-2019) polypoid LCPI cases without an associated cause of polyp, such as adenoma, hyperplastic change, or lymphoid aggregate, were retrieved from 17 (12 female and 5 male) patients. The clinical history and endoscopic findings were noted. A total of 40 conventional LC cases were used as controls. Fisher's exact test was performed to evaluate associations between two variables. The mean age of the patients was 61.1 years. The indication for colonoscopy was chronic watery diarrhea (56%), screening/surveillance (33%), and rectal bleeding (11%). The mean number and size of the polyps was 1.6 and 2.9 mm, respectively. Seventy-six percent were located in the left colon, and 48% were sessile. When biopsied (14/18; 78%), the background colonic mucosa showed LCPI. There was no significant difference in age, gender, and the average number of lymphocytes in the two groups. Hypertension and history of malignancy was more common in the polypoid LCPI group than in the control LC group (P < 0.05). LCPI may present as endoscopic polyps, frequently in patients with hypertension and history of malignancy. Polypoid LCPI may be a harbinger of LCPI in the background nonpolypoid colonic mucosa. A subset of polypoid LCPI (56%) cases represents true LC.

Medical Treatment for Microscopic Colitis: A Community Hospital's Experience

Background

Lymphocytic colitis (LC) is a chronic disorder characterized by watery diarrhea. This study sought to evaluate if LC recurs after therapy, and the time frame in which this occurs. Secondary objectives included length and type of therapy, drug-free intervals, and reasons for drug discontinuation.

Methods

A retrospective chart review between January 1, 2008 and October 30, 2015 of patients with biopsy-confirmed lymphocytic, collagenous, or microscopic colitis was conducted. Patient-reported average bowel movements/day were reviewed. Demographic data, dates of colonoscopy, follow-up, type and dose of medications used, and therapy start/stop dates were reviewed.

Results

Patients presenting with colonoscopic documented LC (n = 114) were predominantly female (88%), Caucasian (97%), with mean bowel movements/day of five. A total of 58/114 (51%) patients were placed on a therapy. Patients taking budesonide saw bowel movements/day reduced from 4.7 to 2.4 compared to 5.8 to 2.8 for those given 5-aminosalicylic acid (5-ASA). First-line medications budesonide and 5-aminosalicylic acid failed in 12/58 (21%) of patients, other drugs also resulted in therapy changes. Thirty-five percent required their initial therapy changed and of those 40% required a second change. Symptom exacerbations were documented during therapy for 19% of patients; therapy changes resulted in good response.

Conclusions

Almost half of all LC cases (56/114) gradually improved without requiring therapy. Seventy-six percent of our treated patients responded well to budesonide when used as the first-line therapy. Similarly, 61.5% responded to 5-ASA. Budesonide was the drug of choice for flares. Tailoring drug therapy to meet individual patient's needs appears to be the best current approach to managing LC.