The rumbling or gurgling noises that originate from the abdomen have a specific scientific name: borborygmi. These sounds are a normal, frequent occurrence produced by the movement of gas and fluids within the gastrointestinal tract. In the vast majority of cases, borborygmi is a benign sign that the digestive system is functioning correctly.
The Mechanism of Borborygmi
The physical sound of borborygmi is generated by a process called peristalsis, which involves wave-like muscle contractions along the digestive tract. These rhythmic contractions serve to mix and propel partially digested food, liquid, and air through the small and large intestines. The resulting noise is simply the sound of gas bubbles and fluids being squeezed and moved through the hollow channels of the gut.
When the stomach is empty, a more powerful, organized series of muscle contractions takes over, known as the Migrating Motor Complex (MMC). The MMC acts as an “interdigestive housekeeper,” sweeping residual debris, bacteria, and indigestible material through the gastrointestinal tract to prepare for the next meal. This cycle typically occurs every 90 to 230 minutes in the fasting state.
Because there is no food present to dampen the vibrations, the forceful contractions of the MMC cause loud stomach growling. This powerful phase of motility is regulated in part by the hormone motilin and helps prevent bacterial overgrowth in the small intestine.
Everyday Triggers
While the MMC is responsible for the loudest growling, borborygmi is also triggered by several common factors. The sensation of hunger initiates a hormonal response that signals the digestive muscles to begin contracting. Even anticipating food can start this process, causing the stomach to growl in preparation for ingestion.
Another frequent cause of noticeable sounds is the simple act of swallowing excess air, or aerophagia. This often happens when a person eats or drinks rapidly, chews gum, or consumes carbonated beverages. The increased volume of swallowed air moves through the intestines, amplifying the sounds produced by normal peristalsis.
Certain foods can also lead to increased gas production, which subsequently causes louder borborygmi. High-fiber foods, such as beans and cruciferous vegetables, or items containing artificial sweeteners and complex sugars, are often poorly absorbed in the small intestine. These undigested components are then fermented by bacteria in the large intestine, releasing gas that increases the internal noise level.
Symptoms That Signal Concern
While stomach growling is typically harmless, it becomes a concern when it is consistently loud, changes dramatically, or is accompanied by other physical symptoms. Persistent, hyperactive bowel sounds coupled with severe abdominal pain should prompt medical attention. This combination can indicate a serious issue such as an intestinal blockage, where the gut muscles contract forcefully to push past an obstruction.
Other concerning signs include borborygmi accompanied by chronic diarrhea or constipation, as these may point to conditions affecting nutrient absorption or gut motility. Conditions like Inflammatory Bowel Disease (IBD), severe food intolerances, or Small Intestinal Bacterial Overgrowth (SIBO) can cause increased, loud rumbling along with bloating and altered bowel habits.
A fever, recurrent nausea, vomiting, or the presence of blood in the stool are additional warning signs that require a prompt medical evaluation. When digestive sounds are significantly abnormal—either extremely loud and high-pitched or noticeably absent—and are tied to systemic symptoms, they indicate a potential health issue.