Intussusception
What is intussusception?
Intussusception is the most common cause of intestinal obstruction in children between 3 months and 6 years of age. It occurs when a portion of the bowel "telescopes" into itself, causing intestinal obstruction.
The condition can progress from intestinal obstruction to necrosis (tissue death) of a segment of the intestine. Initially, blood flow through the intestine is decreased, causing swelling and inflammation. The swelling can lead to perforation (tearing) and generalized abdominal infection. Shock and dehydration can occur very rapidly.
Eighty to 90% of intussusceptions occur in children between 3 months and 3 years of age. They can also occur in older children, teenagers and adults, but this is rare. Boys develop intussusception three to four times more often than girls.
What causes intussusception?
While the exact cause of intussusception is unknown, it often follows an intestinal virus (gastroenteritis) or other viral illness such as a respiratory infection. In response to the virus, the normal lymphatic components of the intestinal wall, known as Peyer's patches, enlarge significantly. This increase causes a thickening of the intestinal wall that encourages intussusception.
A pathologic lead point
When older children develop intussusception, it is usually due to what is referred to as a pathologic lead point. A lead point is a recognizable anatomic abnormality that obstructs the bowel, thus initiating the process of intussusception. Meckel's diverticulum and lymphoma of the intestine are two classic examples of lead points. Intestinal tumors and polyps may also act as lead points.
What medical conditions are associated with intussusception?
Cystic fibrosis and Henoch-Schonlein purpura (HSP) are commonly associated with intussusception. In cystic fibrosis, intussusception is probably a result of the thick material that sticks to the inside of the intestine, thereby partially obstructing (blocking) the intestine. In HSP, a hematoma (bruise) in the intestine may act as a lead point.
Intussusception may occasionally develop following any surgical procedure. Following surgery, differences in how fast intestinal activity returns in different parts of the intestine can cause intussusception.
What segment of the intestine is most frequently affected?
Three types of intussusception can occur:
- Ileocolic – the small intestine "telescopes" into the colon; this is the most common intussusception
- Ileoileal – the small intestine "telescopes" into itself
- Colocolic – the large intestine "telescopes" into itself
Ileoileal or colocolic intussusceptions occur less frequently than ileocolic intussusceptions.
What are the symptoms of intussusception?
A child that is healthy usually has the sudden onset of abdominal pain, in which the child may cry and draw his / her knees to his / her chest. The pain generally comes and goes like cramps, with periods of being without pain, followed by pain that worsens over time. Vomiting and fever usually occur and the child may have a normal or loose bowel movement. The stool may then become mixed with blood and mucus. These bowel movements are referred to as "red currant jelly stools". The child's abdomen generally becomes bloated (distended) and tender. As the condition worsens, vomiting may increase and the child may become pale, weak and listless, showing signs of dehydration or shock.
How is intussusception diagnosed?
A mass may be felt in the abdomen during a physical exam. However, other diagnostic tests are usually necessary. A plain abdominal X-ray sometimes reveals a partial or complete intestinal obstruction, but the diagnosis is confirmed by ultrasonography or a contrast air enema. Air or occasionally a chalky fluid called barium is given into the rectum as an enema. These X-rays will help determine if an intussusception is present.
How is intussusception treated?
Two approaches are used in treating intussusception -- nonoperative reduction and surgery.
Nonoperative reduction
After the diagnosis is confirmed, intussusception is generally reduced (resolved) by gentle pressure exerted within the intestine, using barium or air enemas. However, this technique is not effective for ileoileal intussusceptions, which usually require surgery. Also, if your child is ill with an abdominal infection or has other complications, your physician may choose not to attempt to reduce the intussusception with the enema.
Both barium and air enemas have a low risk (less than 2%) of complications, which could include tearing the intestine.
Surgery
For children who are too ill to have this diagnostic procedure, who may have significant infection in the abdomen, or in whom intussusception does not resolve with the enema, surgery is necessary. If the child has several episodes of intussusception, a surgical procedure may be performed in an attempt to determine the cause of the recurrent intussusception.
With the child under general anesthesia, the surgeon makes an incision in the abdomen, locates the intussusception, and pushes and manipulates the bowel in order to return it to its normal position. If the bowel is severely damaged as a result of the intussusception, additional procedures may be required.
What is the long-term outlook for a child with intussusception?
Although intussusception is a life-threatening disorder when not treated promptly, most children recover completely if diagnostic barium or air enema is performed within 24 hours of initial symptoms.
Intussusception recurs in 5% to 11% of children, and some children may have multiple recurrences. Surgery, even with resection, has a 1% to 4% incidence of recurrence.
Rev. 11/04, 1/05, 4/07
