Hi Dr. Rynne, My Eighteen Year Old Daughter Had Reflux

Hi Dr. Rynne,
My eighteen year old daughter had reflux problems initially and this progressed to severe stomach pain. She had an abdo u/sound which proved clear, a breath test for helicobacter which was negetative. Her bloods appear normal and when she eats potatoes she has severe pain in stomach area and wishes to get sick. She has since given up potatoes for this reason. Can you advise me as to what may be causing acid reflux, bad taste in mouth and abdo pain.

Mary