What is Intussusception?
Intussusception is a condition in which one segment of intestine “telescopes” inside of another, causing an intestinal obstruction (blockage). Although intussusception can occur anywhere in the gastrointestinal tract, it usually occurs at the junction of the small and large intestines. The obstruction can cause swelling and inflammation that can lead to intestinal injury.
The exact cause of intussusception is unknown. In most cases, it is preceded by a virus that produces swelling of the lining of the intestine, which then slips into the intestine below. In some children, it is caused by a condition that the child is born with, such as a polyp or diverticulum.
Intussusception occurs primarily in infants and toddlers. The peak incidence is between 4 and 36 months of age, and it is the most common cause of intestinal obstruction in this age group. Approximately 1 percent of cases are in infants younger than three months, 30 percent between 3 and 12 months, 20 percent between one and two years, 25 percent between two and three years, and 10 percent between three and four years . In a population-wide survey in Switzerland, the yearly mean incidence of intussusception was 38, 31, and 26 cases per 100,000 live births in the first, second, and third year of life, respectively.
Although intussusception is most common in infants and young children, it is important to consider this diagnosis in children outside this age range. Approximately 10 percent of cases are in children over five years, and 3 to 4 percent in those over 10 years. When intussusception occurs outside of the typical age range, it is likely to be associated with a pathologic lead point, which may include reactive lymphoid hyperplasia.
Usually, the ileum enters the cecum. Rarely does a part of the ileum or jejunum prolapse into itself. Almost all intussusceptions occur with the intussusceptum having been located proximally to the intussuscipiens. This is because a peristaltic action of the intestine pulls the proximal segment into the distal segment.
- The part that prolapses into the other is called the intussusceptum.
- The part that receives it is called the intussuscipiens.
- An anatomic lead point occurs in approximately 10% of intussusceptions.
The trapped section of the bowel may have its blood supply cut off, which causes ischemia. The mucosa is sensitive to ischemia and responds by causing sloughing off into the gut. This creates a “red currant jelly” stool, which sloughed mucosa, blood, and mucus. “Red currant jelly” occurs in a minority of cases of intussusception and should be considered in the differential diagnosis of children passing any bloody stool.
Causes of Intussusception
Intussusception is caused by part of the intestine being pulled inward into itself.
The pressure created by the walls of the intestine pressing together causes:
- Decreased blood flow
Intussusception can block the passage of food through the intestine. If the blood supply is cut off, the segment of intestine pulled inside can die. Heavy bleeding may also occur. If a hole develops, infection, shock, and dehydration can take place very rapidly.
The cause of intussusception is not known. Conditions that may lead to the problem include:
- Viral infection
- Enlarged lymph node in the intestine
- Polyp or tumor in the bowel
Intussusception can affect both children and adults. It is more common in boys. It usually affects children ages 5 months to 3 years.
Babies and children with intussusception have intense belly pain that:
- Often begins suddenly
- Makes the child draw the knees up toward the chest
- Makes the child cry very loudly
As the pain eases, the child may stop crying for a while and seem to feel better. The pain usually comes and goes like this, but can be very strong when it returns.
Symptoms also can include:
- A swollen belly
- Vomiting up bile, a bitter-tasting yellowish-green fluid
- Passing stools (poop) mixed with blood and mucus, known as currant jelly stool
- Grunting due to pain
As the illness continues, the child may:
- Get weaker
- Develop a fever
- Appear to go into shock. In this life-threatening problem, a lack of blood flow to the body’s organs makes the heart beat quickly and blood pressure drop.
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.
Complications of Intussusception
Intussusception is a medical emergency. It is a life-threatening illness. If not treated, it can cause serious problems such as:
- Intestinal infection
- The death of intestinal tissue
- Internal bleeding
- A severe abdominal infection called peritonitis
- Dehydration and shock
Your doctor will ask questions about your child’s medical history and symptoms. Your child may be stabilized with an IV line for fluids and a nasogastric tube. This tube is inserted into the stomach through the nose. It relieves pressure on the intestines.
In addition to a physical exam, your doctor will likely order imaging tests to get a better look inside. These may include:
Abdominal X-ray: This safe and painless test uses radiation to figure out whether your child has an obstruction in their intestines or bowel.
Ultrasound: This uses sound waves to create photos of the abdomen.
Air or contrast enema: A soft tube is placed in the rectum and air or a contrast fluid, such as barium, is passed through the tube and into the intestines and bowels. This highlights blocked areas on an X-ray. In some cases, an enema helps straighten out the intestine, fixing the intussusception.
There are a few ways that an intussusception might be treated. There are two types of enemas that may help in reversing the intussusception. These treatments work in many cases but may need to be repeated in a small number of cases.
An air enema is what it sounds like: air is introduced into the intestines. This is done by passing a tube through the anus and into the rectum. Air is moved through the tube and into the intestines. Then some X-rays are taken. The air helps the location of the intussusception be visible on the X-ray films. The air also serves as a treatment, as it helps push the telescoping part of the bowel and move it so that it is no longer folding in on itself.
During this type of enema, barium is introduced through a tube that has been inserted through the anus and into the rectum. X-rays are then taken and the barium helps in visualizing the area of the intestine that has telescoped. The barium also serves as a treatment because it helps push the telescoping part of the intestine back into place.
Ultrasound-guided reduction by barium enema in children with intussusception.
For those that may have a blockage, where stool is not able to pass through the intestine, surgery may be done right away. Surgery might also be done if the intussusception doesn’t respond to the other, less invasive treatments like air or barium enemas, or if there is a perforation (hole in the intestine).
During the surgery a portion of the bowel may need to be removed and then the two ends of the bowel are reconnected (a resection). Surgery may be done laparoscopically, with a few small incisions, or open, which is a larger incision. There will be a need to stay in the hospital for a few days after surgery, until the bowel wakes back up after surgery and the patient can eat normally again.
Prevention of Intussusception
There are no guidelines for preventing intussusception.
- Intussusception is difficult to prevent, since it can be caused by a pre-existing condition
- If other secondary or underlying conditions are already present, then proper care and treatment (if necessary) must be taken, so that the illness does not lead to a complete bowel obstruction