There are many forms and causes of intussusception, but the most common in children is where the last portion of the intestine (the ileum) goes into the first portion of the colon (cecum). This intussusception is an important cause of belly pain and intestinal blockage in infants and requires immediate medical attention. Intussusception occurs in the United States in 2 to 4 per 1000 live births and more commonly (60%) in boys. Intussusception of infancy is seen most commonly between 6 and 10 months of age, with 65% of the children being less than 1 year of age. There seems to be a seasonal incidence, with two peaks occurring (1) in spring and summer and (2) in the middle of winter, corresponding to times of the year with an increased incidence of viral gastroenteritis (GI virus), colds, and flu. While there is no obvious cause, it generally is believed that GI virus leads to swelling of lymph glands in the intestine which leads to one piece of intestine “telescoping” into another.
The common picture of intussusception is that of a well-nourished male infant, about 9 months old, who suddenly awakens from sleep with colicky or crampy belly pain. The pain may pass and the infant may go back to sleep only to be awakened shortly with a similar clinical picture that repeats itself or worsens. These painful events are followed by repeated vomiting that may first resemble the baby’s formula but then changes to a very worrisome yellow or green color (indicating bile). The infant may then pass bloody mucus as a bowel movement which often has a purple or currant jelly color. Passage of bloody stool indicates that damage is occurring to the intestine. Fortunately, the damage is often reversible if the baby receives prompt medical attention at a hospital with expertise in caring for infants. If this condition continues untreated, complete intestinal blockage occurs, which if uncorrected may be fatal in 2 to 4 days.
Pain is seen in 100% of children with intussusception and vomiting in about 80%. Blood in the stool is present in 95% of infants with intussusception although it may not be obvious unless the stool is tested for blood. Occasionally, infants present with signs of illness and are limp and motionless without obvious belly pain. In these cases, the diagnosis may be confused with meningitis. Examination of the infant’s belly may show a lump in the right upper abdomen under the right ribs in about 85% of patients. Fever is common with intussusception in infants.
Once intussusception is suspected, x-rays of the belly should be obtained and a pediatric surgical consultant called. Findings of the initial x-rays may range from essentially normal to complete intestinal blockage. These varied x-ray findings can be confusing and lead to a delay in diagnosis. Currently, ultrasound of the belly is being used in children’s hospitals with increasing frequency to help diagnose intussusception. The next step in the diagnosis and treatment of an infant with intussusception is an enema under x-ray guidance. In the emergency department, prior to beginning the enema, intravenous fluids and antibiotics should be given. In the radiology suite, a barium enema study has been the traditional diagnostic test for evaluation and treatment of intussusception, but air enema has become the standard in most children’s hospitals. A radiologist experienced in performing these specialized procedures is mandatory to optimize the success rate and ensure safety. Anesthesia is not used, but sedation may be helpful during the procedure. Successful correction by enema occurs in 2/3 of patients at specialty centers. PIC barium enema showing an intussusception. Note the barium, which is white, comes up to the infection which is of the large intestine which is the intussusception.
The infant is wrapped to limit movement and a thin tube inserted into the anus. Barium or air is inserted through the tube while the x-ray follows the progress. The height of the barium bag or pressure of the air is carefully monitored to avoid injury. Correction of an intussusception with air or barium can occur if the inner intestine can be “pushed” out of the outer intestine (is “reduced”). This usually is accompanied by disappearance of the abdominal lump and improvement in the child’s appearance. If reduction does not occur immediately, a few more attempts may be made before abandoning the procedure as long as the infant is not getting sicker. The patient is admitted to the hospital when the diagnosis is confirmed even if the problem has been corrected. It is very important that the infant be monitored in the hospital for signs of injury to the intestine, recurrent symptoms, and the after effects of sedation medications. Feedings are started if the child remains well, and the child is discharged shortly thereafter.
If attempts to reduce the intussusception in the radiology suite are not successful, the child is taken to the operating room for surgical correction of the intussusception. The operation usually is performed through a right lower belly incision. Some pediatric surgeons perform the procedure using laparoscopy and several tiny incisions. The surgeon attempts to squeeze the inner piece of intestine out of the outer piece. If the intussusception can be corrected with the squeeze technique and the bowel is not damaged, the intestines are returned to the belly and the appendix is removed. If the intussusception cannot be corrected by the squeeze technique, removal of a portion of intestine, usually involving the end of the small intestine and beginning of the large intestine (colon), is required. It is very rare that a temporary bowel stoma (stool exits the body into a bag on the belly) is required. After surgical correction without intestine removal the child is usually discharged in 24-48 hours. The stay in the hospital can be 5-7 days if removal of intestine is required.
An intraoperative photo of an intussuseption . Note the small intestine is going into the large intestine. The dark area is where the intestine has died and must be removed in this case. In most cases this is not necessary: instead, the small intestine can be pushed/pulled out of the large intestine (reduced).
It is very important that parents are aware that multiple repeat episodes of intussusception can occur up to the age of 2 years. The likelihood of repeat intussusception is the same (5-7%) whether enema or surgical reduction is carried out. The most important factor in caring for a child with initial or repeat intussusception is early diagnosis and treatment.
The current mortality rate in children with intussusception in developed countries is less than 1%. Mortality usually is related to delay in diagnosis, inadequate intravenous fluid and antibiotic therapy, delay in recognizing repeat or partially treated intussusception after enema reduction, and surgical complications.
Daneman A: Intussusception: Issues and controversies related to diagnosis and treatment. Radiol Clin North Am 34:743, 1999.
Controversies in the diagnosis and management of intussusception are reviewed.
Meyer JS, Dangman BC, Buonomo C, et al: Air and liquid contrast agents in the management of intussusception: A controlled, randomized trial. Radiology 188:507-511, 1993.
This controlled study showed that air is as effective as liquid contrast material for diagnosis and treatment.
Ravitch MM, McCune RM Jr: Reduction of intussusception by barium enema: A clinical and experimental study. Ann Surg 128:904, 1948.
This is an excellent review of the diagnosis and management of intussusception by one of the pioneers in the field.
Article and graphics adapted from O'Neill: Principles of Pediatric Surgery. © 2003, Elsevier.