Approximately 10-30% of patients experience at least one episode GI bleeding which is likely multifactorial. It has already been demonstrated that an acquired von Willebrand Syndrome (vWS) develops due to destruction of multimeric vWF. Additionally, it has been shown that these patients have a higher than normal percentage of gastrointestinal angiodysplasia. Whether these are preexisting or develop as a result of de novo angiogenesis from the gut mucosa is unknown. It is thought that the loss of pulsatility and potential hypoxia result in secretion of angiogenic mediators and contribute to the development of angiodysplasia.