The prevalence of small intestinal diverticula (SID) in the population is 0.5-2.3%, and in most cases they are asymptomatic. In the presence of small intestinal bacterial overgrowth this results in chronic diarrhea and malabsorption. When it is complicated by diverticulitis it causes pain and other symptoms of inflammatory bowel disease. Inflammatory process progression may be accompanied by bleeding, invagination, intestinal obstruction, diverticulum abscess and perforation with peritonitis development. SID include separate nosological forms such as paraphateral diverticulum and Meckel's diverticulum. In diagnosis of SID ray and endoscopic methods are crucial. The basis of small intestine diverticular disease treatment is intestinal antiseptics, antibiotics as well as surgical intervention for severe complications. Two cases are discussed, the first one confirms a possibility of development of severe malabsorption syndrome with chronic diarrhea, and the second one is a complication in a form of severe diverticulitis, abscess with perforation and peritonitis.