Summary: Microscopic colitis (MC) belongs to the group of inflammatory bowel diseases (IBD) and often coexists with other autoimmune diseases. The peak incidence of this disease occurs in middle-aged and older populations, mainly in women. The pathogenesis of IBD is complex, multifactorial and poorly understood. Current concepts revolve around innate immunity disorders or changes in the gut microbiome as well as gut barrier dysfunction, all of which lead to the development of subtle inflammatory changes in the intestinal mucosa. The disease usually proceeds without any abnormalities in laboratory, imaging and endoscopic examinations. The basis of its diagnosis is the histological examination of the specimens of the mucosa of the large intestine, which allows to distinguish two main types of MC: collagen inflammation and lymphocytic inflammation; their incomplete forms are also distinguished. The article will discuss the guidelines for the diagnosis and treatment of MC published in 2020, prepared by a group of experts from the European Microscopic Colitis Group (EMCG) and United European Gastroenterology (UEG).