We present two cases of hemangiomatosis of the gastrointestinal tract. The first case describes a 59-year-old patient with upper gastrointestinal hemorrhage due to the blue rubber bleb nevus syndrome. The second case illustrates a 26-year-old patient with recurrent rectal bleeding due to Klippel-Trenaunay syndrome. These two syndromes are distinct disorders characterized by cavernous hemangiomas of the skin, soft-tissue, bones, and viscera. In addition, we review the available literature on the epidemiology, transmission, clinical features, associated conditions, diagnosis, and treatment of these two disorders.