Due to undefined diagnostic criteria and large number of secondary causes of eosinophilia, this disease is often late-detected. Patients are presented with unspecific symptoms such as abdominal pain, diarrhea, weight loss, and its clinical image mostly depends on the depth of eosinophilic infiltration of the intestinal wall. Eosinophilic colitis has bimodal age distribution with highest prevalence in newborns and young adult population. The exact cause of this disease remains unknown. While in infants the cause is most commonly IgE mediated response to cow's milk and soy protein, in adults it's most commonly the result of CD4 Th2 response. Endoscopically observed colon wall changes are unspecific, so biopsy is needed for conformation of the diagnosis and exclusion of other possible diseases. Inflammatory bowel diseases, medicines, parasites, autoimmune connective tissue diseases, idiopathic hypereosinophilic syndrome may create similar clinical presentation and histological findings, which is why eosinophilic colitis is primarily diagnosis of exclusion. In children, after dietary measures are introduced, the disease is self-limiting, whereas in adults long-term treatment is needed because it's a chronic relapsing disease with periods of remission. Corticosteroid therapy has proven to be the most effective, whereas in the cases of severe refractory conditions and development of steroid addiction immunosuppressive therapy is introduced.