My 21 Year Old Daughter Has Suffered From Nausea, Throwing

My 21 year old daughter has suffered from Nausea, throwing up, severe abdominal pain, constipation, diarrhea, for the last 8 years which has lead to anxiety and depression. She has had several colonoscopies
and a few endoscopes. One biopsy came back positive for Crohns, however all of her blood work is always normal. All other biopsies have been negative. Any idea of what could be going on. All blood work is always normal, CT scan normal, Xrays normal