Yes, just recently, six months in, they said they can't tell if it is mal-absorbtion or due to GI bleeding or a malignancy. I had to have a colonoscopy and an endoscopy, I felt like a pig on a spit. The did not find any of the above so it is down to mal-absorbtion of iron. I am taking an iron supplement, 65mg daily, probably for life.
I don't eat a lot of greens or red meat and get most of my protein from fish or cheese and whey supplements. Add to that the 3000 mg of calcium that bariatric patients are required to take; calcium interferes with the uptake of iron. It is no wonder I was anemic. The good news is the iron supplement is working and the washed out feelings I had at the end of the day are past.
Good luck to your friend, she should be okay.