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.
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 the infant's rectum (called barium enema) or swallowed by the infant. Barium looks white on x-rays and outlines the digestive tract, showing the contours and lining of the esophagus, stomach, and small intestine. Barium x-rays can help doctors see whether the lower intestines are in an abnormal position.