Yes, go for it. I did it back in 2003. It will confirm that you have the gastroparesis. Although you will have the diagnosis, it won’t guarantee that doctors will get it! I was still treated like I must not be doing things right or my BS would not be so whacky. Even when I was in the hospital for a week, the doctor managing my BS told me the day I was discharged that my BS baffled him! Although he did not nothing to help me, he was the first doctor to actually believe me that I did nothing to cause it myself.
The test itself is very easy. You aren’t supposed to eat the night before. I was given radioactive eggs to eat - that sounds worse than what it is! There were other food items on the plate but they asked that I at least eat the eggs. You then lay on a table with a camera above that follows the eggs thru your digestive tract. Some test times vary, but an average time for the test is 90 minutes.
The report will contain what percent the food was digested during the test time. You will then be able to find out if you have mild gastroparesis or if it is more severe.
Make sure that you ask for an actual copy of the report. That is one of those reports that you should have if you decide to switch doctors.
Good luck with your test!