Intestinal vascular malformations in children and adolescents are rare but must be considered in the differential diagnosis of gastrointestinal bleeding and chronic anemia. We report a 16-year-old girl who developed chronic iron-deficiency anemia due to recurrent bleeding from multiple angiodysplastic lesions of the stomach, duodenum, and jejunum. The cause of blood loss remained unclear for several years while the girl received numerous blood transfusions. Diagnosis was finally established by capsule endoscopy and double-balloon enteroscopy. Treatment was effectively carried out by argon plasma coagulation. Many systemic vascular malformation syndromes are associated with gastrointestinal lesions. However, as no extraintestinal vascular lesions were present in our patient, diagnosis of a known vascular malformation syndrome seemed unlikely. In addition to the microvascular intestinal malformations, we found a familial congenital asplenia without apparent infectious complications. Thus, the reported case possibly constitutes a so far unpublished variant of the Ivemark syndrome without macrovascular malformations but instead with microvascular malformations. We therefore envison that in times of refined diagnostic techniques the phenotype of the Ivemark syndrome might be expanded by including microvascular malformations.