According to menshealth.com. Yes. A tight belt or waistband is like a tourniquet around your gut, disrupting the flow of your digestive system. "Tight-fitting pants increase abdominal pressure, making it difficult for gas and food to move downward," says Russell Yang, M.D., Ph.D., a professor of gastrointestinal and liver diseases at the Keck School of Medicine at USC. Stomach acid goes back up, and you're more likely to suffer heartburn and acid reflux. A tight belt or waist also magnifies bowel discomfort and stomachaches.