My boyfriend passes gas a lot, every 15 minutes he passes gas...What could it be?

Many possibilities.. There are many possible causes to flatus (passing gas), anything from irritable bowel syndrome, food sensitivities, lactose intolerance, swallowing air during eating, and others. Best to see your doctor to determine the exact cause.
FREQUENT FLATUS. Gas has two sourses one is the air you may swallow while eating food and it mayr pass down to the bowels and produce gas. The other cause is food coming throughthe intestines undigested and causes fomentation with bacteria and and causes flatus. There are certain food like beans, lentils, cabbage, chese, in lactose intolerant milk and milk products. Avoidind these foods and use probiotics andlactase ets.