And you need a definite answer. You have had your entire digestive tract X-rayed. Nothing serious turned up. That takes the edge off a cancer scare. However, you cannot breathe easily until the source of blood is found and treated.
Hemorrhoids are a plausible cause, but that's only guesswork.
You need solid evidence of the cause. A scope examination of your digestive tract might reveal the bleeding site. Keep dogging the doctors until they come up with an answer. She has seen three doctors, all of whom told her that surgery was necessary. She believes herbal medicine can cure everything.