Arteriovenous malformations (AVM's) are the commonest vascular abnormalities of the gut. AVM's or Angiodysplasia may be acquired or inherited as in a hereditary hemorrhagic telangiectasia (HHT). Repeated episodes of gastrointestinal bleeding (GIB), especially in the elderly have been attributed to angiodysplasia. Clinically significant GIB may be also seen in up to 40% of HHT patients, usually in the fourth and fifth decades of life. GIB may manifest both as acute major hemorrhage, slow intermittent blood loss or a combination of these findings and patients may be symptomless, present with acute bleeding or iron deficiency anemia. Recurrent hemorrhage and persistent iron-deficiency anemia is common despite supplemental iron therapy and patients require repeated transfusions. Amongst patients with preexisting co-morbidities, repeated bleeding may lead to significant morbidity and mortality. Furthermore, re-bleeding among these patients consumes a disproportionate share of healthcare resources devoted to multiple admissions, repeated endoscopies and blood transfusions. There are no effective treatment options available currently. The purpose of this study is to determine whether Thalidomide is effective in the treatment of arteriovenous malformations in the gastrointestinal tract.