Intussusception

An intussusception occurs when one part of the small intestine telescopes into another part, usually resulting in the outer layer pinching off the inner layer, resulting in a blockage. Intussusceptions are rarely life threatening, but can be incredibly painful and often resolve themselves without treatment, making detection difficult. Moreover, although most individuals never suffer one, and most people who suffer one never have any outward symptoms, in individuals who develop the condition, it is very likely to re-occur.
Although an intussusception can usually be palpitated, in most cases an ultrasound or x-ray is necessary to detect it. 
An intussusception can also be a symptom of a disorder such as gastroenteritis or Henoch-Schönlein Purpura. 
A barium enema will usually correct the condition, although there is a risk of relapse. If the intestine is damaged, or the blockage persists, surgical intervention may be necessary.
Intussusception at Wikipedia
Category:Gastroenterology