Some diseases can cause bloating and gas, for example, people with diabetes or scleroderma, over time, the activity of the small intestine slows down. This can lead to an overgrowth of bacteria in the gut, which results in poor digestion of carbohydrates and other nutrients. However, even in the absence of obvious disease, some people tend to harbor a large number of bacteria in their small intestine and are prone to farting a lot.