There are few reasons for burning in the stomach.
One of them is known as dyspepsia.
This condition is usually caused by GERD or gastroesophageal reflux disease. Some
other reasons for burning in the stomach can be a peptic ulcer, or inflammation
of the stomach.
One of the ways to determine what is in question is test which is called upper endoscopy. If you want to do this test your doctor should be consulted. He can refuse to do this test if he thinks there is no need for it.
There are few more causes of burning sensation in the stomach such as bacteria which can also cause inflammation and burning sensation. For testing is this the cause are tests as well.