Normal Stomach Noises
Noises within the stomach and bowels are a normal part of gastrointestinal physiology. Most of the time these noises are inaudible to the human ear but when hungry or after eating, bowel sounds may be audible to the person or even others in the near vicinity. This is not abnormal. However loud and excessive bowel sounds (audible and hyperactive) should be investigated, especially if it is persistent or accompanied by other signs and symptoms.
Stomach noises may be described as growling, gurgling or even rumbling. All these noises are medically known as borborygmi (singular ~ borborygmus). Despite the descriptive terms attributed to the various types of stomach noises, it is difficult to isolate the exact cause behind each type of sound. In most cases, the sounds are so similar that these terms are used interchangeably.
The reasons for the various stomach and bowel noises are due to :
- movement of food and chyme through the alimentary tract as the muscle contractions of the gastrointestinal wall pushes it through the gut as well as churning and breaking it down to aid with digestion
- stomach gas and intestinal gas, which is produced by chemical digestion and bacterial action
- indigestible foods and hard substances within the gut
Causes of Loud Stomach Noises
While stomach noises are a normal occurrence, at times these sounds are loud and excessive. This can be disturbing and embarrassing to a person but may not be due to any serious medical disorder. If accompanied by other symptoms like excessive belching, flatulence, abdominal pain, abdominal bloating or changes in bowel movement (like diarrhea or constipation) then it can be quite distressing and is possibly a symptom of some underlying gastrointestinal disturbance.
Broadly, loud and hyperactive stomach noises can be attributed to :
- hypermotility of the gut (excessive movement)
- partial obstruction within the gut
- excessive gas in the gut
- excessive fluid in the gut
- maldigestion or malabsorption
This is where the peristaltic mechanism of the stomach and bowels are overactive. Food is churned and pushed through the gut at a faster rate. Digestion may also be affected. Hypermotility is often associated with diarrhea and may be a result of various causes like :
- infection – infectious gastroenteritis
- chemical irritation – excess alcohol consumption, toxins like with food poisoning and ingested poisons
- functional – diarrhea-predominant irritable bowel syndrome (IBS)
- psychosomatic – anxiety, stress, fear and other strong emotions (refer to Nervous Stomach)
- allergic – food allergies
The movement of food or chyme through a narrowing within the gut may cause unusual noises as the muscles of the gut wall attempt to force the food through the narrowing. These sounds may not be evident if the obstruction lies in the distal parts of the colon where the waste material is almost solid, although it will present with pencil-thin stools.
Some of the causes include :
- foreign bodies
The various causes are discussed further under :
Excess gas in the gut may occur for a number of reasons varying from overeating to gassy foods and bacterial overgrowth. The causes are discussed further under :
The churning of gas with the liquid chyme within the gut, coupled with movement of gas pockets through the gut may contribute to a growling or rumbling noise.
This may be a result of certain process that give rise to osmotic or secretory diarrhea. Osmotic diarrhea is a result of solutes that cannot be absorbed within the gut as with lactose intolerance. Other food intolerances may produce a similar effect. Secretory diarrhea arises due to water being passed into the lumen of the gut as is seen with bacterial toxins, certain secretagogues like diet chewing gum and so on. The excessive fluid will invariably lead to a loose, watery stool.
Typically, gurgling sounds will be evident as hypermotility is often present as well and the rushing of large amounts of fluid is audible.
Malabsorption and Maldigestion
Both maldigestion and malabsorption will lead to excessive gas and/or fluid in the gut. The processes leading to stomach noises have been explained above. Apart from food intolerances, other causes may be related to pancreatitis, gallstones, various other causes of digestive enzyme deficiency or inactivity, as well as non-infectious causes of bowel inflammation, as is seen with inflammatory bowel disease.
Other causes are discussed under :