Other causes of stomach rumbles: 1  Incomplete digestion of food can lead to excess gas in the intestine. 2  Louder rumbles may occur when one is hungry. 3  Stomach rumbles can form further along the gastrointestinal system when air is swallowed while talking, eating, and drinking.
One cup of raw yams contains about 158 calories, whereas 1 cup of raw sweet potatoes contains about 114 calories. Therefore, yams contain about 44 more calories than sweet potatoes for an equal portion.
Cooked sweet potatoes are relatively high in fiber, with a medium-sized sweet potato containing 3.8 grams. The fibers are both soluble (15-23%) in the form of pectin, and insoluble (77-85%) in the form of cellulose, hemicellulose and lignin (12, 13, 14).