Swallowed Air

• When a person eats, drinks, talks or smokes, he make take in excess air. This air can be swallowed and end up in the stomach, where it causes bloating and gas. Carbonated drinks can contribute to this build-up of gas in the stomach and intestines and promote a bloating feeling. The Mayo Clinic says that nervousness and anxiety can also cause a person to gulp down excess air.
  
  

Foods

• Certain foods are more prone to create gas in the stomach and intestines when they are being digested. Common culprits include broccoli, beans, cabbage, brussels sprouts and cauliflower. Certain fruits, such as pears, apples and peaches, may also cause gas and a bloated feeling. Fatty foods are digested more slowly, so a person may feel bloated and over-full after a high fat meal.
  
  

Medical Conditions

• Painful bloating and gas can be caused by many medical conditions such as celiac disease, peptic ulcer disease or an inflamed stomach lining. Heartburn and gastric reflux may also contribute to excess gas and bloating. If you have taken antibiotics, the Mayo Clinic says your intestinal bacteria may have be affected. This can impact your digestion and lead to gas in the intestines.