Malrotation can cause the intestines to be blocked. Because the small intestine is not anchored as it should be, it may twist (volvulus), cutting off the blood supply to the intestines. Why the intestines do not move into the correct location in the abdomen is not known.
Infants with intestinal malrotation often have other birth defects. Although malrotation occurs in infants, it can also occur during early childhood or in adulthood. In some people, malrotation is found incidentally as part of an evaluation for another problem.
(See also Overview of Digestive Tract Birth Defects.)
Infants with intestinal malrotation can suddenly develop vomiting, diarrhea, and abdominal pain and swelling, and these symptoms can also come and go.
If the blood supply to the middle of the intestine is completely cut off because of a volvulus, sudden, severe pain and vomiting develop.
Bile, a substance formed in the liver, may be vomited, making the vomit appear green. Eventually, the abdomen swells.
If an infant is vomiting bile, doctors take x-rays of the abdomen to look for the blockage.
X-rays also are taken after barium is placed in the infant's rectum (called a barium enema) or swallowed by the infant (called an upper gastrointestinal or upper GI series). Barium looks white on x-rays and outlines the digestive tract, showing the contours and lining of the esophagus, stomach, small intestine, and large intestine. Barium x-rays can help doctors see whether the lower intestines are in an abnormal position.
Intestinal malrotation with a volvulus is an emergency that requires immediate surgery. Infants are given fluids by vein (intravenously), and emergency surgery is begun within hours. If not treated rapidly, the defect can result in loss of intestinal tissue or death.
When malrotation is found incidentally in a person who has no symptoms, doctors may opt to surgically repair it, but this is controversial.