Intussusception is a condition in which part of the intestine folds inward and into itself (like a telescope), usually causing swelling, pain, and a complete or partial loss of blood supply to the affected area. Left untreated, the affected intestine may burst or die, causing a serious, life-threatening condition.

Intussusception can occur anywhere along the intestinal tract, but it usually develops between the lower part of the small intestine and the beginning of the large intestine. Intussusception is most common in children; it rarely affects adults. In children, the cause is usually not known. In adults, it is usually related to another intestinal problem.

Symptoms of intussusception in children usually appear suddenly and include:

• Severe abdominal pain that may be continuous or may come and go.
• Decrease in activity (lethargy).
• Passing stools that contain blood or mucus.
• Vomiting. Sometimes vomit appears as a green fluid.

In adults, the symptoms are less severe and less obvious.

Treatment for intussusception varies depending on age and the extent of the problem. Most children can be treated in the hospital with enemas. Sometimes surgery is needed. Most adults are treated with surgery.