Hello Dr. Grief, My husband is 76 years old and has always been strong and healthy. He had open heart surgery 7 years ago that included a triple by-pass and a new aortic valve. He had an excellent recovery. Last year he was diagnosed with type 2 diabetes and he takes metformin and glyberide. His sugar levels are always good and very consistent. Three months ago his doctor noticed that his red blood count was low (120) and the level continued to fall down to 100. He has had an endoscopy, colonoscopy, echocardiogram, and a Trans Esophosegial Echocardiogram - all with excellent results. There is no physical sign of bleeding, yet his RBC remains low even though he is taking 3000 mg of iron daily. He is scheduled to see a haemotologist at the end of this month. Would your recommend other diagnostic tests that might solve this mystery? Thank you! Rosemary