Depending upon the cause of a sour stomach, temporary and often complete relief can be obtained by ingesting the right food and drink. If one is recovering from an upset stomach caused by a virus or food poisoning, the BRAT diet is preferred.
According to The Family Doctor website, the BRAT diet is a treatment for an upset stomach that combines bland, easy-to-digest foods and proper hydration. BRAT is an acronym for bananas, rice, applesauce and toast. These bland foods are non-irritating to a sour stomach and helpful in replenishing some nutrients. Bananas are high in potassium, which provides an essential nutrient for building immunity and strength. The remaining bland foods provide fiber in order to add weight to stool, which is particularly helpful when one is suffering from diarrhea in combination with stomach discomfort. The Family Doctor website reports this diet is good for those in recovery from a stomach virus or for women who are pregnant.
Parents.com recommends natural remedies such as chamomile tea, which relaxes the intestinal muscles; ginger ale or ginger tea, which decrease nausea and neutralize stomach acid; peppermint tea, which aids digestion by improving the flow of bile; or yogurt with live cultures, which helps to flush out intestinal viruses.