Intussusception occurs when a section of the intestine slides inside a nearby part. This movement causes the intestine to fold around itself, the way the parts of a telescope fit around each other.

Intussusception is the most common cause of intestinal obstruction in children under 3 years old. Children are most likely to experience the condition from 6 to 18 months of age.

It’s a medical emergency requiring immediate treatment.

As sections of the intestine fold over each other, food and fluid have a harder time passing through as necessary, and blockages may form. The condition can also reduce blood supply to the affected area, leading to:

  • a tear in the intestine wall
  • infection
  • the possibility of tissue death

Intussusception does not always produce symptoms immediately. When symptoms do begin, they may start suddenly. This is true for both children and adults.

Pain and bowel obstructions are the most common symptoms of intussusception. However, many other symptoms may be present, too.

Symptoms in children

Because intussusception is most common in children who cannot describe their symptoms, it can be challenging to recognize.

Intussusception typically causes fluctuating, or colicky, abdominal pain. Other symptoms such as nausea and vomiting may accompany this pain.

Between these sharp bouts of pain, symptoms may appear to resolve, and children may return to daily activities.

If intussusception results in decreased blood flow in the affected area, this pain may become constant.

Other symptoms may include:

Symptoms in adults

Intussusception is rare in adults and can be difficult to diagnose for this reason. In addition, adults with intussusception will typically have nonspecific symptoms.

When symptoms of adult intussusception are present, they may include abdominal pain as well as nausea and vomiting. These symptoms are typically acute and may come and go.

This can lead some people to go weeks before seeking medical attention.

Intussusception usually occurs in the small intestine. This is the long, winding tube that allows your body to absorb essential nutrients.

Growth in the intestine

It’s not always clear why intussusception forms. In some cases, it’s due to a growth in the intestine, such as a polyp or tumor.

As the muscles within the intestinal wall move back and forth during digestion, tissue may catch on a part of the growth, called a lead point. This may cause some of the nearby tissue to fold over on itself.

If a lead point is the reason, doctors may diagnose the condition as Meckel’s diverticulum, which is a pouch that forms in your small intestine.

But there can be other causes. Some are more common in children than in adults.

Additional causes in children

A virus may play a role, as many children with intussusception have flu-like symptoms and often develop the condition during the fall or winter when flu season peaks.

Celiac disease may also cause intussusception in children.

Additional causes in adults

A polyp, tumor, or scar tissue in the intestine may trigger intussusception in adults.

A digestive disorder, such as Crohn’s disease, may also lead to intussusception. Weight loss surgery or other procedures on the intestine may cause intussusception, too.

Regardless of the cause or age of a person, intussusception requires emergency medical care.

Intussusception can occur in anyone at any age. However, about 70 percent of cases occur during the first 2 years of life, while 90 percent occur in children up to 3 years old. Intussusception is also more common in males.

Other risk factors include an atypical formation of the intestine at birth and a family history of the condition, especially if you have a sibling with an intussusception history.

Children who’ve had one intussusception also have a greater chance of having a recurrence.

If intussusception isn’t treated quickly, it can lead to potentially life threatening situations, such as:

  • dehydration
  • intestinal obstruction
  • a tear, or hole, in the wall of the intestine
  • an infection in the lining of the abdominal cavity (peritonitis)
  • shock
  • sepsis

Diagnosing intussusception usually starts with a review of symptoms and a physical examination.

A doctor may gently press on the abdomen to feel for a lump or other factor, such as tenderness, that could help determine the cause of your child’s symptoms. Doctors will typically then use imaging tests to confirm a diagnosis.

When a doctor suspects intussusception in children, an ultrasound imaging test is the method of choice for diagnosis.

This imaging test uses sound waves and a computer to generate images inside your body. An ultrasound does not expose you to any radiation and can accurately confirm, or rule out, intussusception in almost 100 percent of cases.

Other imaging methods, such as X-rays and CT scans, may also detect intussusception during tests for other causes of abdominal pain.

As cases of intussusception are less common in adults, doctors are more likely to detect the condition when scanning for other abdominal conditions or obstructions.

In some cases, doctors may use a lower gastrointestinal series, or barium enema, to diagnose intussusception. In this test, liquid barium or another fluid is inserted into your rectum to get a detailed X-ray image of the lower part of the small intestine.

If you have a mild case of intussusception, the pressure of the barium insertion can sometimes cause the folded tissue to return to its typical position.

The severity of intussusception is one of the key factors in determining its treatment. Your child’s age and general health are also important. Doctors will typically consider nonsurgical treatment methods first.

Nonsurgical methods

A barium saline or pneumatic pressure enema may be sufficient for treating intussusception. This procedure starts with the injection of air into the intestine. The pressure from the air may push the affected tissue back into its original position.

The fluid administered through the tube in your rectum may also help return the tissue to its proper place.

As explained in a 2017 journal article, nonsurgical methods have an approximate 85 to 90 percent success rate in children.

Surgical methods

If an enema is ineffective or there are signs of bowel necrosis (death of the tissue), surgery may be necessary.

During the surgery

You or your child will be under general anesthesia during surgery, as the operation requires an incision in the abdomen.

Surgeons may carry out the surgery via a keyhole incision and by using small cameras (laparoscopy), or through a larger incision.

The surgeon may be able to restore your intestine to its original position manually. If there is any severe tissue damage, they may need to remove part of the intestine. They will then sew the remaining sections back together.

Surgery is the primary approach for adults with intussusception and children who are very ill with the condition.

Every year in the United States, intussusception affects around 2,000 children in the first 12 months of life.

In young children, nonsurgical treatments may be enough to treat it effectively. However, surgical options are also available for treating intussusception.

You should view symptoms like sudden abdominal pain and changes in your child’s stool seriously. The earlier you seek medical help for symptoms, the sooner your child will feel better, and the lower the risk of complications.