My sister in law who is 69 years old has been losing blood on a huge scale since around 10 years.
She needs a blood transfusion of around 2-3 pints every second week.(true!)
On numerous occasions she has had her insides thoroughly checked out.Including miniture cameras, and still nobody has any idea as to why this is happening to her.
The lost blood cannot be seen.
After a week to two weeks she gets so weak that she can hardly stand.I cannot believe that this has been going on for so long and she is still with us!
IÂ´m sorry not to offer any suggestion.I could suggest finding another doctor.