Intussusception is the sliding of one part of the intestine into another.

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.

The cause of intussusception is not known, although viral infections may be responsible in some cases. Sometimes a lymph node, polyp, or tumor can trigger the telescoping. The older the child, the more likely such a trigger will be found.

Intussusception can affect both children and adults, although most cases occur in children between the age of 6 months and 2 years. It affects boys twice as often as girls.

The first sign of intussusception is usually sudden, loud crying caused by abdominal pain. The pain is colicky and intermittent (not continuous), but recurs frequently, increasing in both intensity and duration.

As the condition progresses, an infant may become weak and may go into shock. Vomiting and fever are common, and some infants will have a bloody, mucus-like bowel movement sometimes referred to as a "currant jelly" stool.

Prompt diagnosis results in the best outcomes.

• Abdominal pain alternating with pain-free periods
• Vomiting
• Stool mixed with blood and mucus
• Shock (pale color, lethargy, sweating)
• Fever

An infant with severe abdominal pain may draw the knees to the chest while crying.

Your doctor will perform a thorough examination, which may reveal a mass in the abdomen. There may also be signs of dehydration or shock.

Tests may include:

• Abdominal x-ray
• Air or contrast enema