Hi there,
It's possible his symptoms could be due to his
gallbladder, especially if he has pain after eating.
Sometimes CT scan doesn't pick up on stones in the gallbladder. I'd recommend he have an
ultrasound to look at his gallbladder, which is a quick and non-invasive test.
Other rare causes of
abdominal pain and how to diagnose them - median arcuate ligament syndrome - this is when the median arcuate ligament (one of the ligaments that holds the diaphragm in place) compresses the
celiac artery and this causes pain after eating due to the lack of blood flow from compression. MRI is the most accurate way to diagnose this.
Hiatal hernia is usually seen on
endoscopy, but not always. This is when the lower esophageal sphincter is in the wrong position, and causes food to reflux from the stomach to the
esophagus. Usually people will complain of
heartburn, but this sometimes can cause pain as well. I'd recommend he start taking an acid reducing medication like prilosec (can be bought over the counter) and see if this helps. A good test to start looking for this is called an upper GI, which is a test where the patient drinks some contrast and a series of X-rays are taken.
I would recommend he stop going to the ER and save it for a true emergency. ER doctors are good at dealing with real emergencies, but not very good at dealing with specific problems such as these. Tt sounds like he's been having these problems for a very long time, and I'd recommend he start by seeing an experience gastroenterologist.
I hope I have answered your questions. Please feel free to contact me should you have any further questions.