It is normal for the stomach to make noises after eating or when a person is hungry. Rumbling, gurgling and growling sounds are usually associated with normal functioning of the digestive system. Sometimes, however, these types of sounds can be a sign of a digestive disorder.
The digestive system creates a system of hormone-like substances that control hunger and appetite. It releases these substances when a person hasn't eaten for a while, triggering the hypothalamus in the brain to send a message of hunger to the stomach and intestines.
Once the stomach and intestines receive a hunger message from the brain, muscles contract and release acids and other digestive fluids. The release of these fluids causes the rumbling sounds. This is a sign that the digestive system is preparing to digest food. These noises can also occur right after one has eaten if the food is just being detected by the digestive system. This may indicate that the stomach had not yet received the hunger message from the brain, possibly due to the fact that the person wasn't really hungry yet.
Rumbling noises can also be triggered by the thought, sight or smell of food. This is common and a sign of normal digestive function. Sometimes stomach noises can occur due to an underlying gastrointestinal disorder, such as irritable bowel syndrome. However, there are usually other symptoms present in such cases. Rumbling noises can also indicate a problem digesting a certain food type, which is common with milk products in individuals who are lactose intolerant. However, other symptoms like nausea or diarrhoea would probably occur as well.
Irritable bowel syndrome commonly causes symptoms of bloating, abdominal cramps, diarrhoea and excess gas. The Mayo Clinic estimates that as many as one in five Americans has symptoms of irritable bowel syndrome, but most people never seek medical help. If symptoms occur, along with a persistent change in bowel habits, it is recommended that one seek medical help to rule out more serious conditions, such as colon cancer, ulcerative colitis or Crohn's disease.
Eating too quickly or talking while eating can cause people to swallow air with their food. Swallowed air is gas that could cause or contribute to rumbling noises. Changing one's eating habits, such as by eating more slowly, may decrease or eliminate the noises.