I Wake Up Every Night Around 2:00 A.m. Due To

I wake up every night around 2:00 a.m. due to pulsating/pounding in my abdomen and a churning stomach. I have had both an upper endoscopy as well as an abdominal CT, both of which showed no cause. The pain and pulsation continue and have gotten worse, continuing during the day. I have been prescribed antacids, though I have repeatedly said that I do not have heartburn or acid reflux. I am at a loss, as my doctor has said that he thinks it is anxiety related and there is nothing he can do for it. Ideas?