Bleeding may occur anywhere along the gastrointestinal (GI) tract, which covers a large surface area and is highly vascularized. Seeing blood in the child's stools, the caregiver and child may become extremely anxious, fearing a devastating diagnosis. The differential diagnosis of lower GI bleeding in infants and children, however, includes numerous possibilities ranging from benign disorders, which require little or no treatment at all, to serious diseases that require immediate intervention. This article reviews a variety of disorders that may produce lower GI bleeding in infants and children. This is Part 2 of a two-part series on GI bleeding in children. Part 1 discussed bleeding from the upper GI tract.