Hypertrophic obstructive cardiomyopathy increases shear stress, leading to von Willebrand Factor degradation and a higher risk of gastrointestinal bleeding.<h4>Case presentation</h4>A 69-year-old male presented to the outpatient clinic with melena, abdominal cramping, and fatigue, along with a history of anemia requiring blood transfusions. This evidence concerns the gene VWF and anemia (phenotype).