Gas that occurs after eating may be caused by foods, certain diseases or swallowing air when eating or drinking, according to WebMD. Gas sometimes causes burping, bloating or flatulence.
Some foods that produce gas include vegetables like cabbage and all varieties of beans. Certain diseases and conditions, such as cystic fibrosis, intestinal parasites and imbalances in intestinal tract bacteria, may cause gas by impairing the body's ability to absorb nutrients, according to WebMD.
Certain behaviors can increase how much air a person swallows, including eating or drinking too fast, smoking, chewing gum, consuming carbonated drinks, and wearing loose dentures, according to the National Institute of Diabetes and Digestive and Kidney Diseases.