The cause of intussusception usually is unknown.
Symptoms include episodes of stomach pain and vomiting that start suddenly and come and go several times per hour, and then later, stools may become bloody.
An air enema can confirm the diagnosis and also treat the condition.
Sometimes surgery is needed.
Intussusception is the most common cause of intestinal blockage among children between the ages of 6 months and 3 years. Boys are affected slightly more than girls, especially after 4 years of age. In most cases, the cause is unknown.
In about 25% of children with intussusception, typically very young children and older children, the sliding (telescoping) is triggered by something in the intestine such as a polyp Polyps of the Colon and Rectum A polyp is a growth of tissue that projects from the wall of a hollow space, such as the intestines. Some polyps are caused by hereditary conditions. Bleeding from the rectum is the most common... read more 
, Meckel diverticulum Meckel Diverticulum A Meckel diverticulum is a saclike outpouching of the wall of the small intestine that is present in some children at birth. Most children do not have symptoms, but sometimes painless rectal... read more , cancerous (malignant) tumor (such as lymphoma Overview of Lymphoma Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs. Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These... read more 
), or immunoglobulin A–associated vasculitis Immunoglobulin A–Associated Vasculitis Immunoglobulin A–associated vasculitis (formerly called Henoch-Schönlein purpura) is inflammation of mainly small blood vessels that most often occurs in children. A rash of reddish purple bumps... read more 
. Children who have cystic fibrosis Cystic Fibrosis (CF) Cystic fibrosis is a hereditary disease that causes certain glands to produce abnormally thick secretions, resulting in tissue and organ damage, especially in the lungs and the digestive tract... read more are also at risk of developing intussusception.
Sometimes the sliding (telescoping) segments return to normal without treatment. If not, the telescoping segments block the intestine and then shut off the blood flow (called ischemia) to the affected area. If blood flow is shut off for more than a few hours, the affected intestine may die (develop gangrene). If a segment of the intestine dies, small holes (perforations) can develop, allowing bacteria to enter the abdominal cavity, resulting in a serious infection inside the abdomen (peritonitis Peritonitis Abdominal pain is common and often minor. Severe abdominal pain that comes on quickly, however, almost always indicates a significant problem. The pain may be the only sign of the need for surgery... read more ).
Symptoms of Intussusception
Intussusception usually causes episodes of stomach pain and vomiting to begin suddenly in a child who is otherwise healthy. The episodes typically last 15 to 20 minutes. At first, the child appears relatively well between episodes.
Later, as ischemia develops, the pain becomes continuous, the child becomes irritable and/or lethargic, and some children pass currant jelly–like stools (dark red stools containing blood and mucus) or develop a fever. Children who have a perforation appear ill and have pain when the abdomen is touched. Sometimes doctors can feel a sausage-shaped mass in the abdomen where the intussusception is located.
Rarely, children who have intussusception do not have pain. Instead, these children appear lethargic as though they are intoxicated.
What Is Intussusception?
One part of the intestine slides into another, much like the parts of a collapsible telescope. As a result, the intestine is blocked.  |
Diagnosis of Intussusception
Imaging tests, typically ultrasonography
A doctor may suspect intussusception based on the child’s symptoms and a physical examination.
Ultrasonography Ultrasonography Ultrasonography is a type of medical imaging that uses high-frequency sound (ultrasound) waves to produce images of internal organs and other tissues. During an ultrasound, a device called a... read more 
is done to confirm the diagnosis.
Less commonly, computed tomography Computed Tomography (CT) Computed tomography (CT) is a type of medical imaging that combines a series of x-rays to create cross-sectional, detailed images of internal structures. In computed tomography (CT), which used... read more 
(CT) is done to evaluate the child for abdominal pain and can diagnose intussusception.
If an imaging study that was done for some other reason shows an intussusception but the child has no symptoms, treatment may be delayed or in come cases not needed. However, the doctor will advise parents to be alert for symptoms, such as pain, vomiting, and irritability.
Treatment of Intussusception
Air enema
Surgery
If ultrasonography confirms intussusception, an air enema is done.
Air enema
With an air enema, the doctor puts air into the child’s rectum through a small tube and then takes x-rays. The pressure of the air usually pushes the telescoped portion of the intestine back into place. The x-rays show whether the procedure was successful. If the air enema is successful, the child can be sent home after an overnight hospital stay. In a small number of children, intussusception can happen again.
Surgery
Surgery is needed for intussusception if
The child has signs of intestinal perforation.
The air enema does not correct the intussusception.
The disorder returns.
If the disorder returns, surgery is done to correct the disorder and also to look for a polyp, tumor, or other abnormality that could explain why the intussusception returned.
