Definition of Abdominal sounds:

Abdominal sounds are the noises made by the intestines.

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.

Common 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 reduce intestinal movements 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