Here is an excellent article from Columbia University.
Some quick stats: 1 in 100 people in the US have CD. 97 of those people don't know they have it. Only 1 in 6 people who have CD have typical gastrointestinal symptoms. Many are completely asymptomatic. Untreated CD can lead to cancer, diabetes, and a host of other autoimmune diseases. 80% of medical research in the US is done by drug companies and because CD is treated without drugs there is very little attention given to the disease. Most physicians receive their continuing education from drug reps. Physicians taught in the US are still taught that CD is a rare disease of childhood.