Soups that are low in fat and sodium can be gentle on your stomach. Soups high in fat can cause inflammation in your abdomen, which can exacerbate your symptoms and make you feel worse. Most soups are high in sodium and can irritate your stomach. Choose low-sodium chicken soup or broth as one of the most gentle options. Low-sodium and low-fat cream soups can be soothing as well. Soup or broth can also help prevent dehydration, which can be a danger with the stomach flu.