It sounds to me as though you need to see a Gastroenterologist who specializes in stomach and bowel disorders. Since you are of age, and don't require your parents permission to do anything, I'd check to see if your insurance company requires prior authorization for you to see specialists. If they do, demand that your primary care physician submit that information to the insurance company. They will want to see you again first, but you have to follow the steps for it to occur. There are several issues that could possibly be the case here, some of which of constipation, allergies to foods/surroundings, dumping syndrome, tortuous bowels.
Please call your insurance company asap to get the ball rolling. If no referral is required, then make the appointment with a GI (gastrointestinal) MD ASAP!
found out that i tested positive for Helicobacter pylori thank you hopefully i make a smooth recovery.