Children

The first sign of intussusception in an otherwise healthy infant may be sudden, loud crying caused by belly pain. Infants who have belly pain may pull their knees to their chests when they cry.

The pain of intussusception comes and goes, usually every 15 to 20 minutes at first. These painful episodes last longer and happen more often as time passes.

Other symptoms of intussusception include:

• Stool mixed with blood and mucus — sometimes referred to as currant jelly stool because of its appearance.
• Vomiting.
• A lump in the belly.
• Weakness or lack of energy.
• Diarrhea.

Not everyone has all of the symptoms. Some infants have no obvious pain. Some children don't pass blood or have a lump in the belly. And some older children have pain but no other symptoms.

Adults

Intussusception is rare in adults. Also, because symptoms of the disorder often overlap with the symptoms of other disorders, it's more challenging to identify. The most common symptom is belly pain that comes and goes. Nausea and vomiting also may occur. People sometimes have symptoms for weeks before seeking medical attention.

Intussusception requires emergency medical care. If you or your child develops the symptoms listed above, seek medical help right away.

In infants, pulling the knees to the chest and crying are often symptoms of belly pain.

Your intestine is shaped like a long tube. In intussusception, one part of your intestine — usually the small intestine — slides inside an adjacent part. This is sometimes called telescoping because it's similar to the way a collapsible telescope slides together.

In some cases in adults, the telescoping is caused by a growth in the intestine, such as a polyp or a tumor, called a lead point. The typical wavelike contractions of the intestine grab this lead point and pull it and the lining of the intestine into the bowel ahead of it. In most cases, however, no cause can be found for intussusception.

Children

In most cases of intussusception in children, the cause is unknown. Intussusception seems to occur more often in the fall and winter. And because many children with the problem also have flu-like symptoms, some suspect a virus may play a role in the condition. Sometimes, a lead point can be identified as the cause of the condition — most frequently the lead point is a pouch in the lining of the small intestine (Meckel's diverticulum).

Adults

In adults, intussusception is usually the result of a medical condition or procedure, including:

• A polyp or tumor.
• Scar-like tissue in the intestine, known as adhesions.
• Weight-loss surgery such as gastric bypass or other surgery on the intestinal tract.
• Swelling in the intestines due to diseases such as Crohn's disease.

Risk factors for intussusception include:

• Age. Children — especially young children — are much more likely to develop intussusception than adults are. It's the most common cause of bowel obstruction in children between the ages of 6 months and 3 years.
• Sex. Intussusception more often affects boys.
• Irregular intestinal formation at birth. Intestinal malrotation is a condition in which the intestine doesn't develop or rotate correctly. This increases the risk of intussusception.
• Certain conditions. Some disorders can increase the risk of intussusception, including:
  • Cystic fibrosis.
  • Henoch-Schonlein purpura, also known as IgA vasculitis.
  • Crohn's disease.
  • Celiac disease.

Intussusception can cut off the blood supply to the affected portion of the intestine. If left untreated, lack of blood causes tissue of the intestinal wall to die. Tissue death can lead to a tear in the intestinal wall, called a perforation. This can cause an infection of the lining of the abdominal cavity, known as peritonitis.

Peritonitis is a life-threatening condition that requires immediate medical attention. Symptoms of peritonitis include:

• Belly pain.
• Swelling in the belly area.
• Fever.
• Vomiting.

Peritonitis may cause your child to go into shock. Symptoms of shock include:

• Cool, clammy skin that may be pale or gray.
• A weak and rapid pulse.
• Breathing that may be either slow and shallow or very rapid.
• Anxiety or agitation.
• Extreme listlessness.

A child who is in shock may be conscious or unconscious. If you suspect your child is in shock, seek emergency medical care right away.

Your or your child's health care provider will start by getting a history of the symptoms of the problem. The provider may be able to feel a sausage-shaped lump in the belly. To confirm the diagnosis, your provider may order:

• Ultrasound or other abdominal imaging. An ultrasound, X-ray or computerized tomography (CT) scan may reveal intestinal obstruction caused by intussusception. Imaging will typically show a "bull's-eye," representing the intestine coiled within the intestine. Abdominal imaging also can show if the intestine has been torn (perforated).

Treatment of intussusception typically happens as a medical emergency. Emergency medical care is required to avoid severe dehydration and shock, as well as prevent infection that can occur when a portion of intestine dies due to lack of blood.

Treatment options for intussusception may include:

• A water soluble contrast or air enema. This is both a diagnostic procedure and a treatment. If an enema works, further treatment is usually not necessary. This treatment can actually fix intussusception 90% of the time in children, and no further treatment is needed. If the intestine is torn (perforated), this procedure can't be used.

  Intussusception recurs up to 20% of the time, and the treatment will have to be repeated. It is important that a surgeon be consulted even if treatment with enema is planned. This is because of the small risk of a tear or rupture of the bowel with this therapy.

• Surgery. If the intestine is torn, if an enema is unsuccessful in correcting the problem or if a lead point is the cause, surgery is necessary. The surgeon will free the portion of the intestine that is trapped, clear the obstruction and, if necessary, remove any of the intestinal tissue that has died. Surgery is the main treatment for adults and for people who are acutely ill.

In some cases, intussusception may be temporary and go away without treatment.

Emergency medical care is required to treat intussusception. You may not have much time to prepare for an appointment.

What to expect from your doctor

Your child's health care provider is likely to ask you several questions, including:

• When did your child begin experiencing stomach pain or other symptoms?
• Does your child's pain appear to be continuous — or is it happening off and on?
• Does the pain begin and end suddenly?
• Has your child experienced nausea, vomiting or diarrhea?
• Have you noticed any blood in your child's stool?
• Have you noticed any swelling or a lump in your child's abdomen?

What you can do in the meantime

Don't give your child any nonprescription medications to treat symptoms before the appointment. Don't give your child anything to eat if you see any of the symptoms of intussusception. Seek immediate medical attention.