Irritable Bowel Syndrome (IBS)

Gas in the gastrointestinal tract is normal. Passage of gas by belching or as flatus (gas per rectum) is normal. Gas in the digestive tract comes from two main sources - swallowed air and through the breakdown of certain undigested foods. Gas is produced by the breakdown of these foods by bacteria normally present in the large intestine. Swallowed air is a common cause of gas in the stomach. A small amount of air is swallowed with eating and drinking, particularly when eating or drinking quickly. Loose dentures, chewing gum and smoking also increase the amount of air swallowed.