Intussusception is the infolding, like the closing of a telescope, of a segment of the small intestine into the adjacent but more distal ("downstream") segment of the intestine. (The term "intussusception" is pronounced "in-tu-su-ception" with the accent on the "in". It comes from the Latin "intus", within + "suscipere", to receive = to receive within).

Causes

Intussusception is caused by part of the intestine being pulled inward into itself. This can block the passage of food through the intestine. If the blood supply is cut off, the segment of intestine pulled inside strangles and can die.
The pressure created by the walls of the intestine pressing together causes irritation, swelling, and decreased blood flow. The intestine can die, and the patient can have significant bleeding. If a hole occurs, infection, shock and dehydration can take place very rapidly.

Symptoms

A child with intussusception may have recurring episodes of severe abdominal pain and may scream and draw up his or her knees from severe cramping. During a bout of pain, the child may look pale. The cramping lasts from about 1 to 5 minutes. Afterward, the child may seem normal, only to have another episode of pain from 5 to 30 minutes later. Some children have an episode of pain before passing stool. As the condition gets worse, the child may become listless and weak between painful episodes

Diagnosis

Intussusception is often suspected based on history and physical exam, including observation of Dance's sign. Per rectal examination is particularly helpful in children as part of the intussusceptum may be felt by the finger. A definite diagnosis often requires confirmation by diagnostic imaging modalities. Ultrasound is today considered the imaging modality of choice for diagnosis and exclusion of intussusception due to its high accuracy and lack of radiation. A target-like mass, usually around 3cm in diameter, confirms the diagnosis.

Prevention

Prevention of death can be accomplished with immediate medical care, within the first 24 hours. Once intussusception is suspected, emergency measures should be initiated. Untreated intussusception is almost always fatal. There is an increased chance for death if the disorder is not treated within 48 hours.

Treatment

When your child arrives at the hospital, the doctors will first stabilize his or her medical condition. This includes giving your child fluids through an intravenous (IV) line and putting a tube through the child's nose and into the stomach (nasogastric tube) to allow the intestines to decompress.
Doctors can often use a barium or air enema to correct the telescoping intestine and successfully treat intussusception. If an enema works, no further treatment is necessary.

If your child is dehydrated, he or she will need a drip of fluids for a while before treatment starts. Your child will also need a nasogastric tube, which is passed up the nose, down the food-pipe and into the stomach. This will drain off the stomach and bowel contents, and ‘vent’ any air that has built up, which will make your child more comfortable.

Surgery

Sometimes surgery is needed for intussusception. Surgery may be needed if:
Enemas have not corrected the problem after two or three attempts.
Health professionals suspect that the intestine has been damaged and needs to be repaired.
The child is very ill or the intestine has ruptured, leaking stool into the abdomen.