P806 Increasing incidence of microscopic colitis in a population-based cohort study in a French speaking region of Switzerland

H. Maye1, S. Ekaterina2, A. Schoepfer3

1University Hospital Fribourg, Gastroenterology, Fribourg, Switzerland, 2Institute of Social and Preventive Medicine, Public Health, Bern, Switzerland, 3CHUV - Centre Hospitalier Universitaire Vaudois, Gastroenterology and Hepatology, Lausanne, Switzerland


Microscopic colitis (MC) is a chronic inflammatory disease of the colon presenting with watery diarrhoea. It encompasses two entities, namely lymphocytic colitis (LC) and collagenous colitis (CC). Population-based epidemiologic data the frequency and natural history of microscopic colitis are scarce. We evaluated the clinical presentation at diagnosis, incidence and prevalence of MC in Cantons of Vaud and Fribourg, Switzerland.


Cantons of Vaud and Fribourg lie in the French-speaking, Western part of Switzerland. As of 12/2017, both cantons together had a population of 1,109,230 inhabitants. We contacted all Pathology institutes (n = 6) in both cantons in order to identify patients that have been diagnosed with microscopic colitis. We then performed a chart review in all adult and paediatric gastroenterology practices in order to identify MC patients and to assess the incidence, prevalence, their clinical, endoscopic, and histological characteristics as well as natural history.


Out of 252 patients, a total of 218 fulfilled the diagnostic criteria for MC, whereof 123 had LC and 95 had CC. Age at first diagnosis of MC was 63.2 ± 14.3 years (62.8 ± 14.3 for LC, 63.7 ± 14.4 years) and median diagnostic delay was 1.1 ± 3.1 years. Symptoms leading to MC diagnosis were diarrhoea (100%), abdominal pain (31.7%), weight loss (31.2%), bloating (20.6%), fatigue (9.6%), and nausea/vomiting (3.2%). The following risk factors were found in MC patients: statins (27.1%), aspirine (23.4%), proton pump inhibitors (22.5%), serotonine reuptake inhibitors (22.5%), smoking (20.2%), non steroidal anti-inflammatory drugs (14.2%), and neuroleptics (4.1%). Median exposure time to risk factors was 55 months (IQR 33–78, range 1–280 months). Associated auto-immune diseases (celiac disease, type 1 diabetes, autoimmune gastritis, autoimmune thyroiditis, rheumatoid arthritis) were found in 14 patients (6.4%). No patient was diagnosed with MC prior to 1994. Incidence of MC significantly increased from 0.36/100,000 inhabitants in 1994–1997 to 6.85/100,000 inhabitants in 2017 (p = 0.025). The cumulative prevalence of MC, LC, and CC in 2017 was 19.65/100,000, 11.09/100,000, and 8.56/100,000, respectively.


The incidence and cumulative prevalence of MC shows a steady increase in an indicator region of roughly 1 million inhabitants in French speaking part of Switzerland.