Intestinal obstruction

Definition

Intestinal obstruction is a partial or complete blockage of the bowel that results in the failure of the intestinal contents to pass through.

Alternative Names

Paralytic ileus; Intestinal volvulus; Bowel obstruction; Ileus; Pseudo-obstruction - intestinal; Colonic ileus

Causes, incidence, and risk factors

Obstruction of the bowel may due to:

• A mechanical cause, which simply means something is in the way
• Ileus, a condition in which the bowel doesn't work correctly but there is no structural problem

Paralytic ileus, also called pseudo-obstruction, is one of the major causes of intestinal obstruction in infants and children. Causes of paralytic ileus may include:

• Chemical, electrolyte, or mineral disturbances (such as decreased potassium levels)
• Complications of intra-abdominal surgery
• Decreased blood supply to the abdominal area (mesenteric artery ischemia)
• Injury to the abdominal blood supply
• Intra-abdominal infection
• Kidney or lung disease
• Use of certain medications, especially narcotics

In older children, paralytic ileus may be due to bacterial, viral, or food poisoning (gastroenteritis), which is sometimes associated with secondary peritonitis and appendicitis.

Mechanical causes of intestinal obstruction may include:

• Abnormal tissue growth
• Adhesions or scar tissue that form after surgery
• Foreign bodies (ingested materials that obstruct the intestines)
• Gallstones
• Hernias
• Impacted feces (stool)
• Intussusception
• Tumors blocking the intestines
• Volvulus (twisted intestine)

Symptoms

• Abdominal distention
• Abdominal fullness, gaseous
• Abdominal pain and cramping
• Breath odor
• Constipation
• Diarrhea
• Vomiting

Signs and tests

While listening to the abdomen with a stethoscope your health care provider may hear high-pitched bowel sounds at the onset of mechanical obstruction. If the obstruction has persisted for too long or the bowel has been significantly damaged, bowel sounds decrease, eventually becoming silent.

Early paralytic ileus is marked by decreased or absent bowel sound.

Tests that show obstruction include:

• Abdominal CT scan
• Abdominal x-ray
• Barium enema
• Upper GI and small bowel series

Treatment

Treatment involves placing a tube through the nose into the stomach or intestine to help relieve abdominal distention and vomiting.

Surgery may be needed to relieve the obstruction if the tube does not relieve the symptoms, or if there are signs of tissue death.

Expectations (prognosis)

The outcome varies with the cause of the obstruction.

Complications

Complications may include or may lead to:

• Electrolyte imbalances
• Infection
• Jaundice
• Perforation (hole) in the intestine

If the obstruction blocks the blood supply to the intestine, the tissue may die, causing infection and gangrene. Risk factors for tissue death include intestinal cancer, Crohn's disease, hernia, and previous abdominal surgery.

In the newborn, paralytic ileus that is associated with destruction of the bowel wall (necrotizing enterocolitis) is life-threatening and may lead to blood and lung infections.

Calling your health care provider

Call your health care provider if persistent abdominal distention develops and you are unable to pass stool or gas, or if other symptoms of intestinal obstruction develop.

Prevention

Prevention depends on the cause. Treatment of conditions (such as tumors and hernias) that are related to obstruction may reduce your risk.

Some causes of obstruction cannot be prevented.

References

Evers, BM Small Intestine. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. St. Louis, Mo: WB Saunders; 2008:chap 48.

Fry RD, Mahmoud N, Maron DJ, Ross HM, Rombeau J. Colon and rectum. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. St. Louis, Mo: WB Saunders; 2008:chap 50.