I think if you already have an appointment with the pediatrician, then you should go see him. Also you might need a referral from the pediatrician to see a gastroenterologist.
Gastroparesis is tested for using a gastric emptying scan (I recommend the 4 hour version). She will go in the morning having not eaten anything after midnight and she will be given a meal that usually consists of eggs, toast with jam, and some juice. There is be a small amount of radioactive material in the food (not harmful). Then she will lay under a scanning machine that will show how much of the food is in her stomach for the fist 30 minutes, then at 1 hour, 2 hours, 3 hours, and 4 hours. In between those measurements she can get up and do whatever until it is time for the next scan. The scan is painless and nothing touches her. Then after a couple days the doctor will get back to you and tell you how much her stomach emptied and if she has gastroparesis. This test is very very easy (not invasive at all) and the hardest part of the test is eating the meal.
Gastroparesis ranges from mild to severe. If the gastroparesis is mild, she will have to adjust her diet to low-fiber, low-fat, multiple small meals throughout the day. She may also be put on a medication to help with stomach emptying like domperidone or reglan. If those don't work there are other options like a gastric stimulator (an implanted device), a NJ or J tube (a tube that goes into her small intestine and she is tube fed that way instead of eating). I have pretty severe gastroparesis and so I am 100% fed through my J tube. Let me know if you have any more questions.
So do you think I shouldnt even bother going to the pediatrician first? I was ready about gastroparesis. How do they test for it?? Is it evasive? Is it a serious condition? Thanks.
Welcome to the gastroenterology community! I would recommend that you see a gastroenterologist about this and get a gastric emptying scan to look for gastroparesis which is slow emptying of the stomach.