New insights and challenges in microscopic colitis

Abstract

Microscopic colitis (MC) is described as an inflammatory bowel disease characterized by chronic, bloodless diarrhea with normal or close to normal endoscopic findings. Histopathological examination reveals two subtypes: collagenous colitis (CC) and lymphocytic colitis (LC), which are indistinguishable clinically. The disease debuts typically in middle-aged patients, but can occur at all ages, including children. A female predominance is found in both CC and LC, but is not confirmed by others in LC. The etiology is unclear, but the disease has been assumed to be of autoimmune origin. However, several etiologies may render a microscopic inflammation in the mucosa; this is a common, universal reaction to a variety of irritants in contact with the intestinal lumen. Furthermore, some patients with a microscopic inflammation in their colonic mucosa have no symptoms, or are suffering from constipation or abdominal pain, rather than diarrhea. Recently, a discussion was initiated calling into question the overdiagnosing of symptoms and pointing out the danger of exacerbating people's perception of their ailments, of weakening their eligibility in health insurance, of overprescription of drugs, and thus the increasing cost to the society of health care. In the light of this discussion, this review will highlight histopathological and clinical features of MC, and discuss the diagnosis and management of this disease. Perhaps, the intestinal mucosa has no other mode by which to react than an inflammatory response, irrespective of the presence or absence of autoimmunity. Thus, to better identify and classify subgroups of MC, and to clarify and correctly handle the inflammatory changes, this field of research stands to benefit from a review of the results and experience gained to date.

Aquaporins in Infection and Inflammation

“…The cause of MC is unknown. Risk factors that include age, the use of proton-pump inhibitors and NSAIDs have been identified to increase the risk of MC [216,251]. Stress is a factor that some people find affects their bowel movements and sometimes results in diarrhoea.…”

“…Since stool consistency has been shown to be the main determinant for impaired QOL [215], budesonide treatment has a great impact on the patient's everyday life. Risk factors for MC include age, use of nonsteriodal anti-inflammatory drugs (NSAIDs) or proton-pump inhibitors, antidepressants or antipsychotic drugs [216]. Smoking has also been shown to have negative effects on the treatment response and stool consistency [217].…”

Microscopic colitis and its associations with complications observed in classic inflammatory bowel disease: a systematic review

“…However, only two studies adjusted for smoking, alcohol intake and BMI [20,23]. This may affect the conclusions, since several lifestyle habits are associated with MC [3,[32][33][34]. No study adjusted for drug consumption.…”

“…Infiltration of lymphocytes is found in the mucosa during many conditions, e.g., celiac disease, viral and bacterial enteritis, drugs and other autoimmune diseases. In these cases, MC should be considered a secondary phenomenon, and not a primary, idiopathic disease [32]. This confounder could explain differences in results between studies, and why LC had more associations with rheumatic diseases treated with several anti-inflammatory drugs [18], which could elicit lymphocyte infiltration in the mucosa [31].…”

A case of collagenous colitis with cryptogenic organizing pneumonia

“…Finally, this case was diagnosed as having lansoprazole induced collagenous colitis. Already there are many reports about relevance between PPI and collagenous colitis [5,[7][8][9]. This case had a past history of administration of rabeprazole against peptic ulcer, and there was no diarrhea during administration.…”