Abdominal sounds

Definition

Abdominal sounds are the noises made by the intestines.

Alternative Names

Bowel sounds

Considerations

Abdominal sounds (bowel sounds) are made by the movement of the intestines as they push food through. Since the intestines are hollow, bowel sounds can echo through the abdomen much like the sounds heard from water pipes.

Most bowel sounds are harmless and simply mean that the gastrointestinal tract is working. A doctor can check abdominal sounds by listening to the abdomen with a stethoscope (auscultation).

Although most bowel sounds are normal, there are some instances in which abnormal bowel sounds provide valuable information about the health of the body.

Ileus is a condition in which there is a lack of intestinal activity. Many medical conditions may lead to ileus. It is important to evaluate it further because gas, fluids, and the contents of the intestines can build up and break open (rupture) the bowel wall. The doctor 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, and also occur normally for a short time after the use of certain medications 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 can sometimes occur with diarrhea and after eating.

Abdominal sounds are always evaluated together with symptoms such as:

• Gas
• Nausea
• Presence or absence of bowel movements
• Vomiting

If bowel sounds are hypoactive or hyperactive and there are other abnormal symptoms, it is important for you to have continued follow-up with your health care 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.

Causes

Most of the sounds you hear in your stomach and intestines are due to normal digestion and are no need 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:

• 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. Reduced nerve activity can result from:
  • Blood vessel blockage
  • Bowel blockage
  • Chemical imbalances such as hypokalemia
  • Infection
  • Overexpansion of the bowel
  • Trauma

Other causes of hypoactive bowel sounds:

• Drugs that slow down movement in the intestines such as opiates (including codeine), anticholinergics, and phenothiazines
• General anesthesia
• Radiation to the abdomen
• Spinal anesthesia
• Surgery in the abdomen

Other causes of hyperactive bowel sounds:

• Crohn's disease
• Diarrhea
• Food allergy
• GI bleeding
• Infectious enteritis
• Ulcerative colitis

When to Contact a Medical Professional

Call your health care provider if you have any symptoms such as:

• Bleeding from your rectum
• Nausea
• Diarrhea or constipation that continues
• Vomiting

What to Expect at Your Office Visit

The doctor or nurse 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?

The doctor may order more tests. Tests may include:

• Abdominal CT scan
• Abdominal x-ray
• Blood tests
• Endoscopy

If there are signs of an emergency, you will be sent to the hospital. A tube will be placed through your nose or mouth into the stomach or intestines. This empties your intestines. Usually, 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 medication to reduce symptoms and to treat the cause of the problem. (The specific medication depends on the situation.) Some people may need surgery right away.

References

Mcquaid K. Approach to the patient with gastrointestinal disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 134.

Squires RA, Postier RG. Acute abdomen. In:Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbookof Surgery. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 47.

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