Gas in digestive system is part of the normal process of digestion. Getting rid of excess gas, either by burping or passing gas (flatus) is normal. Gas pain may occur if gas is trapped or not moving well through digestive system. Symptoms include burping, passing gas, pain, cramps or a knotted feeling, bloating, distention. Certain high-fiber foods may cause gas, including beans and peas (legumes), fruits, vegetables. whole grains, carbonated beverages, artificial sweeteners. Gastric trouble is treated by gastroenterologists.