Intussusception is a condition where part of the intestine slides into an adjacent part of the intestine. It is usually seen in children under the age of 5, and is characterized by abdominal pain, vomiting, and bloody stool. As the condition progresses, the abdominal pain may become severe and the patient may become dehydrated. The types of intussusception can vary, ranging from a simple form to a more complex form, which can lead to serious complications. Symptoms can include fever, abdominal distension, and shock. Treatment may include surgery, but in some cases, it may be possible to reduce the intussusception without surgery.