Intestinal obstruction

Causes and Risks:
Obstruction of the bowel can occur either from ileus (a non-mechanical obstruction) or mechanical causes. Paralytic ileus is a one of the major causes of obstruction in infants and children. The causes of paralytic ileus may include:
  • intraperitoneal infection
  • mesenteric ischemia (decreased blood supply to the support structures in the abdomen)
  • injury to the abdominal blood supply
  • after intra-abdominal surgery
  • kidney or thoracic disease
  • metabolic disturbances (such as decreased potassium levels)

Paralytic ileus can cause gastroenteritis , electrolyte imbalances , and pneumonia in infants; and peritonitis , ruptured appendix, and uremia in older children. Paralytic ileus is marked by abdominal distention , absent bowel sounds (no noise heard when listening to abdomen) and very little pain (as compared to mechanical obstruction). The incidence of paralytic ileus is high in comparison to mechanical obstruction but paralytic ileus is not as significant as mechanical obstruction.

Mechanical obstruction occurs when movement of material through the intestines is physically blocked. The mechanical causes of obstruction are numerous and may include:

  • hernias
  • postoperative adhesions or scar tissue
  • impacted feces (stool), gallstones
  • tumor
  • granulomatous processes (abnormal tissue growth)
  • intussusception (a condition where the intestine "telescopes" in on itself), volvulus (a twisted intestine)
  • foreign bodies

If the obstruction blocks the blood supply to the intestine, the tissue may die, causing infection and gangrene. Risk factors are intestinal malignancy , Crohn's disease , hernia , and previous abdominal surgery. The incidence is 2 out of 2,000 people.

Prevention:
Prevention depends on the cause. Treatment of conditions (such as tumors and hernias) that are related to obstruction may reduce the risk. Some are not preventable.

Symptoms:



Signs and Tests:
Listening to the abdomen with a stethoscope may show high-pitch bowel sounds at the onset of mechanical obstruction. If the obstruction persists to long or the bowel is significantly damaged the bowel sounds decrease until they become silent. Paralytic ileus has decreased or absent bowel sound initially.

Tests that show obstruction include:

Other tests may include:



Treatment:
The objective of treatment is to decompress the intestine with suction, using a nasogastric tube inserted into the stomach or intestine. This will relieve abdominal distention and vomiting .

Surgery to relieve the obstruction may be necessary if decompression by nasogastric tube does not relieve the symptoms, or if strangulation of the bowel or gangrene is suspected.

Prognosis:
The outcome varies with the cause of the obstruction.

Complications:

  • infection
  • gangrene of the bowel



Call Your Healthcare Provider:
Call your health care provider if persistent abdominal distention develops with inability to pass stool or gas, or if other new symptoms develop.


This illustration shows the major organs of the digestive system. Their relative sizes and positioning in the body are also demonstrated.



This abdominal X-ray shows a stomach filled with fluid and a swollen (distended) small bowel, caused by a blockage (obstruction) in the intestines. A solution containing a dye (barium) that is visible on X-rays was swallowed by the patient (upper GI series).



This abdominal X-ray shows thickening of the bowel wall and swelling (distention) caused by a blockage (obstruction) in the intestines. A solution containing a dye (barium), which is visible on X-ray, was swallowed by the patient (the procedure is known as an upper GI series).



This abdominal X-ray shows an intestinal condition in which a loop of bowel has slipped into another section of bowel (intussusception), causing swelling, reduced blood flow, obstruction, and tissue damage. Intussusception requires emergency treatment (barium enema or surgery) to prevent intestinal tissue death (necrosis), intestinal perforation, peritonitis, and death.



A GI series in a patient with a twisted bowel (volvulus).



X-rays of the abdomen are important in diagnosing the presence of small bowel obstruction. When obstruction occurs, both fluid and gas collect in the intestine. They produce a characteristic pattern called "air-fluid levels". The air rises above the fluid and there is a flat surface at the "air-fluid" interface.