Is Physical Activity Harmful If Suffering Form Chronic Blood Loss Through Bowels?

I sure hope so. My husband has had a LOT of blood transfusions due to gastrointestinal bleeding over the past three years. Most recently in December. We were told during that hospitalization that he has Heyde's syndrome. He has aortic valve stenosis. It seems that he looses blood pretty quickly at times. He is scheduled to see a cardio thoracic surgeon in two days. We believe he is in need of another transfusion already. He is constantly passing blood through his bowels. I started noticing that he has tried to be more active since his hospital stay and was wondering if he should avoid increased activity and if that could accelerate the blood loss?