How does food intolerance lead to bloating?

Bloating is an enlarged abdomen caused by excess gas. Most people have bloating because they can't digest certain foods. In some people, certain foods, including dairy products, some fruits and vegetables, and wheat, can't be completely broken down in their small intestines. The undigested food moves into the colon, and bacteria in the colon continues to break down the food, and this process results in the formation of gas.