What Causes Constant Vomiting Sensation?

Hi, my wife has been sick for a while now a little over a year now that is. It started with stomach pains and not being able to eat very much. We ve been to the doctors, she got a colonoskapy, she got blood tests, the doctor thought ibs. So she started with immodium but she still couldn t eat barely anything. Now the doctor thinks it gluten intolerancy but she completely cut off all gluten products, and yet again she s still getting sick. She ll feel overheated, like she s about to throw up or have extreme cases of diarrhea or constipation. Now she s starting to lose hope she s finding it hard to even keep water down. What could this be? Please help she doesn t deserve to have this happen to her. Any possible ideas as to what this is or solutions