Bloody diarrhea is a common problem in children. It is important to distinguish bloody diarrhea from other causes of rectal bleeding. Bacterial infections and parasitic infestations are responsible for most of the cases. Milk allergy is a frequent cause in young infants. Chronic inflammatory bowel disease occurs in older children. The cause is most often apparent after a thorough history and physical assessment is performed and the stool is examined for pathogens. Proctosigmoidoscopy with biopsy is the procedure of choice if the stool tests for pathogens are negative. A few children require further diagnostic evaluation by colonoscopy and/or radiographic procedures.