Beans, cucumbers, and pickles may especially increase the amount of rectal gas. Swallowed air travels partway down the esophagus and is then forced back up, or may enter the stomach, forming a bubble, enlarging with each new addition of air that is the source of belches and a bloated feeling. Diagnosis is usually via observance of symptoms, but excessive abdominal gas should be investigated to exclude such serious causes as lactose intolerance, intestinal infection, or malabsorption diseases.
Some people simply produce more gas than others.
If a fiber-rich diet is eaten daily, the body will often adjust and produce less gas after a time. Decreasing intake of carbonated beverages and not drinking through a straw may help reduce gas. Many different infections affect the gastrointestinal tract, a significant number lumped under the term gastroenteritis, commonly referred to as stomach flu. In addition, other microorganisms, such as Salmonella bacteria, Shigella bacillus, and intestinal parasites, may cause gastroenteritis. Typhoid fever and cholera are rare in the United States and other industrialized societies, but still occur in underdeveloped areas where food and water may be contaminated by unsanitary conditions.