The most common cause of intestinal obstruction in children under the age of 3 is a painful condition called intussusception. It occurs when one part of the intestine slides into the section next to it.

Intussusception is considered a medical emergency, but it’s treatable with both nonsurgical and surgical approaches. The risk of developing this intestinal obstruction tends to diminish as a child grows older.

Read on to learn more about intussusception in both adults and children, including symptoms, causes, diagnosis, and treatment.

Intussusception occurs when a section of 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.

As a result, food and fluid have a harder time passing through the intestine. The condition can also reduce blood supply to the affected area, leading to:

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

Intussusception doesn’t always arrive with noticeable symptoms. When symptoms do begin, they usually start suddenly. This is true for both children and adults.

Pain is the most common symptom of intussusception, but there are other symptoms that may be present, too. Older children and adults may have only pain and none of the other common symptoms.

Symptoms in children

Because intussusception is most common in children under 3, they may not be able to describe their symptoms. The first clue of trouble may be a sudden cry of pain.

Young children may bend over or try to pull their knees up to their chest. Bouts of abdominal pain may come and go every 15 minutes or so. They may last longer each time until treatment begins.

Other symptoms in children may include:

  • nausea and vomiting
  • diarrhea
  • stool mixed with blood and mucus
  • fever
  • little or no energy

You may also be able to feel a small lump in the lower abdomen.

Symptoms in adults

Among the challenges of diagnosing intussusception in adults are that it’s rare and is usually accompanied by nonspecific symptoms.

When symptoms of adult intussusception are present, they may include abdominal pain as well as nausea and vomiting. These symptoms may come and go, often leading people to go weeks before seeking medical attention.

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

Growth in the intestine

It’s not always clear why intussusception forms, though 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 the growth, called a lead point. This may cause some of the nearby tissue to fold over on itself.

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

If a lead point is to blame, the problem may be diagnosed as Meckel’s diverticulum, a pouch that forms in the small intestine.

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 the patient, intussusception requires emergency medical care.

Intussusception can occur in anyone at any age. The American Pediatric Surgical Association reports that about 75 percent of cases occur during the first 2 years of life, while 90 percent occur in children up to age 3. Intussusception is also more common in males.

Abnormal formation of the intestine at birth is another risk factor for intussusception. Children who’ve had one intussusception have a greater chance of having more.

A family history of the condition, especially having a sibling with an intussusception history, can also increase a child’s chances of having this condition.

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.

Imaging tests are usually required to confirm the diagnosis. These tests may include one or more of the following:

  • Abdominal X-ray. This imaging test may show a blockage in the intestine.
  • Upper gastrointestinal (GI) series or barium swallow. An upper GI series relies on a special liquid that, when swallowed, coats the upper GI tract. The liquid improves the visibility and detail of the upper GI tract on an X-ray.
  • Lower GI series or barium enema. In this test, liquid barium or other fluid is inserted into the rectum (the end of the large intestine) to get a detailed X-ray image of the lower part of the small intestine. In cases of mild intussusception, the pressure of the barium insertion can sometimes cause the folded tissue to return to its normal position.
  • Ultrasound. This test uses sound waves and a computer to generate images of inside the body. An ultrasound of the intestine can often detect tissue problems or circulation disruptions.

The severity of intussusception is one of the key factors in determining its treatment. The age of the child and their general health is also considered.

Usually, a nonsurgical procedure will be considered first.

Nonsurgical methods

A barium or saline enema may be sufficient, as it 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 the rectum may also help return the tissue to its proper place.

Surgical methods

If an enema is ineffective, surgery may be needed. General anesthesia is necessary as the operation requires an incision in the belly.

The surgeon may be able to manually restore the intestine to its normal, healthy position. If any tissue has been damaged, part of the intestine may have to be removed. The remaining sections are then sewn back together.

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

Intussusception occurs in about 1 out of 1,200 children, so it’s not an uncommon condition.

In young children, nonsurgical treatments may be enough to effectively treat it.

Take 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 be out of distress, and the lower the risk of complications.