Intussusception

Intussusception is a serious problem with the intestine, or bowel. When intussusception occurs, part of the intestine collapses into itself. It folds into itself like a collapsible tube--like an antenna folding up--with one part slipping inside another part. This makes the intestines not work properly.

Causes

Intussusception is most common in infants and occurs three times more often in males than in females. It typically occurs between ages 3 months and 3 years, with a peak incidence between ages 6 and 9 months.

Studies suggest that intussusception may be linked to viral infections because seasonal peaks are noted-in the late spring and early summer, coinciding with the peak incidence of enteritis, and in the midwinter, coinciding with the peak incidence of respiratory tract infections.

The cause of most cases of intussusception in infants is unknown. In older children, polyps, alterations in intestinal motility, hemangioma, lymphosarcoma, lymphoid hyperplasia, or Meckel's diverticulum may trigger the process. In adults, intussusception usually results from benign or malignant tumors (65% of patients). It may also result from polyps, Meckel's diverticulum, gastroenterostomy with herniation, or an appendiceal stump.

When a bowel segment (the intussusceptum) invaginates, peristalsis propels it along the bowel, pulling more bowel along with it; the receiving segment is the intussuscipiens. This invagination produces edema, hemorrhage from venous engorgement, incarceration, and obstruction. If treatment is delayed for longer than 24 hours, strangulation of the intestine usually occurs, with gangrene, shock, and perforation.

Signs and symptoms

The most common symptom of intussusception is sudden onset of intermittent pain in a previously well child. However, each child may experience symptoms differently. The pain may be mistaken for colic at first, and occurs at frequent intervals. Infants and children may strain, draw their knees up, act very irritable, and cry loudly. Your child may recover and become playful in-between bouts of pain, or may become tired and weak from crying.

Vomiting may also occur with intussusception, and it usually starts soon after the pain begins. Your child may pass a normal stool, but the next stool may look bloody. Further, a red, mucus or jelly-like stool is usually seen with intussusception.

Symptoms of intussusception may resemble other conditions or medical problems. Please consult your child's physician for a diagnosis.

In adults, intussusception produces nonspecific, chronic, and intermittent symptoms, including colicky abdominal pain and tenderness, vomiting, diarrhea (occasionally constipation), bloody stools, and weight loss. Abdominal pain usually localizes in the right lower quadrant, radiates to the back, and increases with eating. Adults with severe intussusception may develop strangulation with excruciating pain, abdominal distention, and tachycardia.

Diagnosis

A physician will obtain a medical history and perform a physical examination of your child. Imaging studies are also done to examine the abdominal organs, and may include:

• abdominal x-ray - a diagnostic test which may show intestinal obstruction.
• barium enema - a procedure performed to examine the large intestine for abnormalities. A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray) is given into the rectum as an enema. An x-ray of the abdomen shows strictures (narrowed areas), obstructions (blockages), and other problems. On some occasions, the pressure exerted on the intestine while inserting barium will help the intestine to unfold, correcting the intussusception.

Treatment

In children, therapy may include hydrostatic reduction or surgery. Surgery is indicated for children with recurrent intussusception, for those who show signs of shock or peritonitis, and for those in whom symptoms have been present longer than 24 hours. In adults, surgery is always the treatment of choice.

Hydrostatic reduction

During hydrostatic reduction, the radiologist drips a barium solution into the rectum from a height of not more than 3' (0.9 m); fluoroscopy traces the progress of the barium. If the procedure is successful, there is free flow of contrast into the ileum and the mass disappears. Inability to show this suggests incomplete reduction and necessitates surgical exploration.

Surgery

During surgery, manual reduction is attempted first. After compressing the bowel above the intussusception, the surgeon attempts to milk the intussusception back through the bowel. If manual reduction fails or if the bowel is gangrenous or strangulated, the surgeon performs a resection of the affected bowel segment. An incidental appendectomy is also performed.

Prevention

Prevention of death can be accomplished with immediate medical care, within the first 24 hours. Once intussusception is suspected, emergency measures should be initiated. Untreated intussusception is almost always fatal. There is an increased chance for death if the disorder is not treated within 48 hours.