Hello, mslora710, I am assuming that your mother is probably over 45-50 yrs. of age. 17 years of recurrent GI bleeds with no diagnosis is not acceptable at this day and age. awe do have a lot of tests now that we did not have a short few years ago. I am sure your mother has had several upper endoscopies to check for bleeding sources and also has had few colonoscopies by experts.Unless the bleeding is active at the time of exam , it is possible to miss the source. Some of the most common causes are abnormal blood vessels called Angiodysplasia which can be present any where in the entire gastro-intestinal tract .The bleeding scans, angiograms, injecting the dye into the blood vessel may find the site of bleeding. Latest technology is the Capsule Endoscopy where a person swallows a capsule which has photographic capabilities and a transmitter which can capture hundreds of pictures which are downloaded to a computer and analyzed. There are some limitations as well with this procedure and some contraindications. Som of the other conditions diagnosed with this include Crohn s disease, small bowel tumors including cancer and lymphomas. Hope you can discuss this with your doctor. Wish her well.