He is a male around 22 years old. And it's been ongoing for 2-3 years now. But he has no associated diarrhea or constipation. But he does have bloating and decreased appetite?

R/O IBS. IBS = irritable bowel syndrome is a diagnosis of exclusion. SX can be managed You need a full exam and blood work. Especially screen for H pylori . Also stool screen x 3 for occult blood /parasite/hpylori . you also need an EGD/colonoscopy. While you are getting these items checked out you should ditch to a gluten free high fiber diet . Ie gutbliss.com and Wholeapproach.com. Also 64-80oz water.