What Causes Pain In Chest While Swallowing?

My son has been having chest pains when he swallows since Thursday. It is very uncomfortable espeucially with food. He has taken a Prilosec every morning since then but it hasn't gone away. He rode the roller coaster on Thursday. On Friday the Dr. did an ECG and said it was okay. His lungs were also clear. His temperature and blood pressure are normal.