Infantile persistent diarrhea series are not well documented in the literature. Evaluating the literature, the aim of this study was to document persistent diarrhea cases followed in our center and to constitute a practical diagnostic algorithm for the pediatrician by means of surveying methods. Diarrheas lasting more than 14 days were accepted as persistent diarrhea. Forty-one persistent diarrhea cases aged 0-24 months were investigated in this study. The cases were evaluated for the presence of mucus and/or leukocytes in stool and were thus divided into two major groups as colitis or enteropathies. For the differential diagnosis of the persistent colitis group, stool cultures, dietary restrictions, complete blood count, acute phase reactants, pathergy test, gene analysis for familial Mediterranean fever and Behçet's disease, colonoscopy, and biopsies were performed. In the persistent enteropathy group, differential diagnosis was made with the following tests: serum and stool electrolytes, arterial blood gases, serum albumin, total protein, lipid profile, stool alpha-1 antitrypsin level, stool pH, presence of stool fat and reducing substance, endoscopy, and biopsies. The 27 persistent enteropathy cases included 7 celiac disease, 5 intestinal lymphangiectasia, 2 microvillus inclusion disease, 2 abetalipoproteinemia, and 11 cow's milk allergy. The 13 cases of the infantile colitis group included 1 Behçet's disease, 1 colitis ulcerosa and 11 cow's milk allergy. Two cases presenting as pancreatic insufficiency were diagnosed as cystic fibrosis. One case was diagnosed as cystic fibrosis plus cow's milk allergy. Reviewing the literature, these cases represent the largest non-infectious infantile group of persistent diarrheas. A practical diagnostic algorithm for persistent diarrheas has been constituted.