Digestion and hunger are typical causes of grumbling or growling noises in the stomach, according to Healthline. When a person is hungry, substances in the brain trigger food craving. This leads to the delivery of signals to the stomach, causing the digestive system muscles to contract and make noises.
The small and large intestines usually create abdominal sounds during digestion when the intestines process food, explains Healthline. Digestion occurs a few hours after consuming food and takes place during the day and at night.
Hypoactive, or reduced, abdominal sounds signify the slowing down of intestinal activity, whereas hyperactive bowel sounds refer to very audible noises that other people can also hear, states Healthline. Occasional occurrences of these stomach noises happen to most people. However, individuals who frequently experience abdominal grumbling should consult a health care provider, especially if other symptoms accompany the noise. Accompanying symptoms that possibly indicate an underlying medical condition include too much gas, constipation, frequent diarrhea, vomiting and nausea.
Underlying illnesses that may cause abdominal sounds and other symptoms include blood clots, hernias, infections and trauma, notes Healthline. Ulcers, food allergies, blockage of bowels and inflammatory bowel disease are also potential causes. Doctors typically perform tests such as computed tomography scan, endoscopy and blood testing to diagnose the cause.