Gas, bloating, and belching are associated with a variety of conditions but are most commonly caused by functional gastrointestinal disorders. These disorders are characterized by disordered motility and visceral hypersensitivity that are often worsened by psychological distress. An organized approach to the evaluation of symptoms fosters trusting therapeutic relationships. Patients can be reliably diagnosed without exhaustive testing and can be classified as having gastric bloating, small bowel bloating, bloating with constipation, or belching disorders. Functional dyspepsia, irritable bowel syndrome, and chronic idiopathic constipation are the most common causes of these disorders. For presumed functional dyspepsia, noninvasive testing for Helicobacter pylori and eradication of confirmed infection (i.e., test and treat) are more cost-effective than endoscopy. Patients with symptoms of irritable bowel syndrome should be tested for celiac disease. Patients with chronic constipation should have a rectal examination to evaluate for dyssynergic defecation. Empiric therapy is a reasonable initial approach to functional gastrointestinal disorders, including acid suppression with proton pump inhibitors for functional dyspepsia, antispasmodics for irritable bowel syndrome, and osmotic laxatives and increased fiber for chronic idiopathic constipation. Nonceliac sensitivities to gluten and other food components are increasingly recognized, but highly restrictive exclusion diets have insufficient evidence to support their routine use except in confirmed celiac disease.