Dyskeratosis congenita (DC) is a rare inherited disorder characterized by reticular skin pigmentation, oral cavity leukoplakia, and nail dystrophy. Bone marrow failure in DC can only be cured by allogeneic hematopoietic stem cell transplantation (HSCT). After a nonmyeloablative, matched unrelated donor transplant, the 21-year-old patient experienced severe lower gastrointestinal tract hemorrhage caused by diffuse colitis. The etiology remained unclear. Diffuse colitis with life-threatening hemorrhage has now been reported in 3 DC patients after unrelated allogeneic HSCT. To identify the underlying causes and the disease-specific risks, and to allow for prevention and/or optimal management, data should be prospectively collected.