Colitis is a disease of the colon caused by inflammation of the intestinal wall. Depending on the duration they are divided to acute and chronic, according to the evoker they are divided to infectious and non-infectious. Clinical signs of colon inflammation are not only namely abdominal pain and diarrhoea. In the clinical picture there often dominate dehydration, mineral unbalance, high inflammatory activity, worsening of an underlying disease, anaemic syndrome, sideroepenia, hypoproteinemia, malnutrition, development of acute kidney impairment, development of sepsis or an acute abdominal event. Many times these signs dominate and diarrhoea or abdominal pain, mainly in geriatric patients, is in the background. Even if colitis is a domain of a gastroenterologist, an internist has a complex and integrated view of a patient. Knowledge of different types of colitis can contribute to rational considerations in diagnostics and treatment, or correct timing of colonoscopy.