Abdominal sounds are the noises made by the intestines.
Abdominal sounds (bowel sounds) are made by the movement of the intestines as they push food through. The intestines are hollow, so bowel sounds echo through the abdomen much like the sounds heard from water pipes.
Most bowel sounds are normal. They simply mean that the gastrointestinal tract is working. A health care provider can check abdominal sounds by listening to the abdomen with a stethoscope (auscultation).
Most bowel sounds are harmless. However, there are some cases in which abnormal sounds can indicate a problem.
Ileus is a condition in which there is a lack of intestinal activity. Many medical conditions may lead to ileus. This problem can cause gas, fluids, and the contents of the intestines to build up and break open (rupture) the bowel wall. The provider may be unable to hear any bowel sounds when listening to the abdomen.
Reduced (hypoactive) bowel sounds include a reduction in the loudness, tone, or regularity of the sounds. They are a sign that intestinal activity has slowed.
Hypoactive bowel sounds are normal during sleep. They also occur normally for a short time after the use of certain medicines and after abdominal surgery. Decreased or absent bowel sounds often indicate constipation.
Increased (hyperactive) bowel sounds can sometimes be heard even without a stethoscope. Hyperactive bowel sounds mean there is an increase in intestinal activity. This may happen with diarrhea or after eating.
Abdominal sounds are always evaluated together with symptoms such as:
- Presence or absence of bowel movements
If bowel sounds are hypoactive or hyperactive and there are other abnormal symptoms, you should continue to follow-up with your provider.
For example, no bowel sounds after a period of hyperactive bowel sounds can mean there is a rupture of the intestines, or strangulation of the bowel and death (necrosis) of the bowel tissue.
Very high-pitched bowel sounds may be a sign of early bowel obstruction.
Food passes from the mouth through the esophagus to the stomach. The stomach churns the food and breaks it down further with hydrochloric acid and an enzyme called pepsin. The process of breaking food down in the stomach takes a few hours. From there, it goes to the duodenum, which the first part of the small intestine. Within the duodenum, digestive bile produced by the liver and stored in the gallbladder along with enzymes from the pancreas break it down more. Enzymes are chemicals that speed up the digestion of specific types of food. For example, the enzyme trypsin breaks down the protein in steak, and lipase helps to break down fat. Humans don’t have enzymes to break down certain plant fibers, which is why they can’t be fully digested. The enzyme called lactase breaks down the sugar in milk. Sometimes, lactase is not produced by the body at all, or in insufficient amounts, making a person lactose intolerant. So, when a person who is lactose intolerant eats ice cream or yogurt, the digestive system gets bloated and expels gas. Once everything is broken down, the small intestine absorbs the nutrients the body needs. From there the nutrients go into the bloodstream and to the liver, where poisons are removed. Undigested food and water continue through the small intestine and go into the large intestine, where water is reabsorbed. Then, at the end of the line, feces are eliminated through the rectum and anus.
Most of the sounds you hear in your stomach and intestines are due to normal digestion. They are not a cause for concern. Many conditions can cause hyperactive or hypoactive bowel sounds. Most are harmless and do not need to be treated.
The following is a list of more serious conditions that can cause abnormal bowel sounds.
Hyperactive, hypoactive, or missing bowel sounds may be caused by:
- Blocked blood vessels prevent the intestines from getting proper blood flow. For example, blood clots can cause mesenteric artery occlusion.
- Mechanical bowel obstruction is caused by hernia, tumor, adhesions, or similar conditions that can block the intestines.
- Paralytic ileus is a problem with the nerves to the intestines.
Other causes of hypoactive bowel sounds include:
- Drugs that slow down movement in the intestines such as opioids (including codeine), anticholinergics, and phenothiazines
- General anesthesia
- Radiation to the abdomen
- Spinal anesthesia
- Surgery in the abdomen
Other causes of hyperactive bowel sounds include:
When to Contact a Medical Professional
Contact your provider if you have any symptoms such as:
- Bleeding from your rectum
- Diarrhea or constipation that continues
What to Expect at Your Office Visit
The provider will examine you and ask you questions about your medical history and symptoms. You may be asked:
- What other symptoms do you have?
- Do you have abdominal pain?
- Do you have diarrhea or constipation?
- Do you have abdominal distention?
- Do you have excessive or absent gas (flatus)?
- Have you noticed any bleeding from the rectum or black stools?
You may need the following tests:
- Abdominal CT scan
- Abdominal x-ray
- Blood tests
If there are signs of an emergency, you will be sent to the hospital. A tube may be placed through your nose or mouth into the stomach or intestines. This empties your intestines. In most cases, you will not be allowed to eat or drink anything so your intestines can rest. You will be given fluids through a vein (intravenously).
You may be given medicine to reduce symptoms and to treat the cause of the problem. The type of medicine will depend on the cause of the problem. Some people may need surgery right away.
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Landmann A, Bonds M, Postier R. Acute abdomen. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. St Louis, MO: Elsevier; 2022:chap 46.
McQuaid KR. Approach to the patient with gastrointestinal disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 123.
Last reviewed on: 10/20/2022
Reviewed by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.