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. Since the intestines are hollow, bowel sounds can echo throughout the abdomen much like the sounds heard from water-pipes.

The majority of the bowel sounds are harmless and simply indicate that the gastrointestinal tract is working. Abdominal sounds are evaluated by listening to the abdomen with a stethoscope (auscultation).

While the majority of bowel sounds are normal, there are some instances where 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 this but it is important to evaluate it further because gas, secretions, and intestinal contents can accumulate and 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 bowel sounds. They indicate a slowing of intestinal activity. 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 are sometimes heard even without a stethoscope. Hyperactive bowel sounds reflect an increase in intestinal activity. This can sometimes occur with diarrhea and after eating.

Abdominal sounds are always evaluated in conjunction with symptoms such as nausea, vomiting, presence or absence of bowel movements, or gas. If bowel sounds are hypoactive or hyperactive, along with abnormal symptoms, continued evaluation by a health care provider is important.

For example, absent bowel sounds after a period of hyperactive bowel sounds are significant and can indicate that rupture of the intestines, or strangulation of the bowel with subsequent death (necrosis) of the bowel tissue may have occurred.

Most of the sounds you hear your stomach and intestines make are due to normal digestion and are no need for concern. Many conditions may cause hyperactive or hypoactive bowel sounds. Most are harmless and require no treatment.

The following are a list of more serious conditions that can cause abnormal bowel sounds.

Hyperactive, hypoactive, or absent bowel sounds:

• Mechanical bowel obstruction is caused by hernia, tumor, adhesions, or similar conditions that can physically block the intestines.
• Blocked blood vessels prevent the intestines from getting proper blood flow. For example, blood clots can cause mesenteric artery occlusion.
• Paralytic ileus is a problem with the nerves to the intestines. Reduced nerve activity can result from infection, overdistended bowel, trauma, bowel obstruction, vascular obstruction, and chemical imbalances such as hypokalemia.

Other causes of hypoactive bowel sounds:

• Drugs that reduce intestinal movements such as opiates (including codeine), anticholinergics, and phenothiazines
• General anesthesia
• Spinal anesthesia
• Irradiation of the abdomen (radiation therapy for cancer)
• Surgery in the abdomen (may cause reduced bowel sounds for 1 to 5 days)

Other causes of hyperactive bowel sounds:

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