A stomach rumble, also known as a bowel sound, peristaltic sound, abdominal sound, bubble gut or borborygmus (pronounced ˌbɔɹbəˈɹɪɡməs; plural borborygmi), is a rumbling, growling or gurgling noise produced by movement of the contents of the gastrointestinal tract as they are propelled through the small intestine by a series of muscle contractions called peristalsis. A trained healthcare provider can listen to these intestinal noises with a stethoscope, but they may be audible enough to be heard with the naked ear as the fluid and gas move forward in the intestines (in the vicinity of, but not actually within the stomach). The lack of bowel sounds is indicative of ileus, intestinal obstruction, or some other serious pathology. The scientific name borborygmus is related to the 16th-century French word borborygme, itself from Latin, ultimately from Ancient Greek βορβορυγμός (borborygmós). The Greek term is probably onomatopoetic in origin. Other causes of stomach rumbles: Incomplete digestion of food can lead to excess gas in the intestine. In humans, this can be due to incomplete digestion of carbohydrate-containing foods, including milk and other dairy products (lactose intolerance or the use of α-glucosidase inhibitors by diabetics), gluten (protein in wheat, barley, and rye) (coeliac disease), fruit, vegetables, beans, legumes, and high-fiber whole grains. In rare instances, excessive abdominal noise may be a sign of digestive disease, especially when accompanied by abdominal bloating, abdominal pain, diarrhea or constipation. Some examples of diseases that may be associated with this symptom include carcinoid neoplasm and coeliac sprue. Louder rumbles may occur when one is hungry. The sound of air moving around the lumen of the stomach is amplified by the empty space. Around two hours after the stomach has been emptied, it sends signals to the brain, which tells the digestive muscles to restart peristalsis in a wave called the migrating motor complex. Food left behind after the first cycle is swept up, and the vibrations of the empty stomach cause hunger.