Malrotation and Volvulus
If the bowel does not rotate completely during embryonic development, problems can occur. This condition is called malrotation. Normally, the caecum is located in the lower right part of the abdomen. If the caecum is not positioned correctly, the bands of thin tissue that normally hold it in place may cross over and block part of the small bowel.
Also, if the small bowel and colon have not rotated properly, the mesentery may be only narrowly attached to the back of the abdominal cavity. This narrow attachment can lead to a mobile or floppy bowel that is prone to twisting, a disorder called volvulus.
Malrotation is also associated with other gastrointestinal (GI) conditions, including Hirschsprung's disease and bowel atresia.
Malrotation is usually identified in infants. About 60 percent of these cases are found in the first month of life. Malrotation affects both boys and girls, although boys are more often diagnosed in infancy.
In infants, the main symptom of malrotation is vomiting bile. Bile is a greenish-yellow digestive fluid made by the liver and stored in the gallbladder. Symptoms of malrotation with volvulus in older children include vomiting (but not necessarily vomiting bile), abdominal pain, diarrhoea, constipation, bloody stools, rectal bleeding, or failure to thrive
Various imaging studies are used to diagnose malrotation:
- x rays to determine whether there is a blockage. In malrotation, abdominal x rays commonly show that air, which normally passes through the entire digestive tract, has become trapped. The trapped air creates an enlarged, air-filled stomach and upper small bowel, with little or no air in the rest of the small bowel or the colon.
- upper GI series to locate the point of intestinal obstruction. With this test, the patient swallows barium to coat the stomach and small bowel before x rays are taken. Barium makes the organs visible on x ray and indicates the point of the obstruction. This test cannot be done if the patient is vomiting.
- lower GI series to determine the position of the colon. For this test, a barium enema is given while x rays are taken. The barium makes the colon visible so the position of the caecum can be determined.
- computed tomography (CT) scan to help determine and locate the intestinal obstruction.
Malrotation in infants is a medical emergency that usually requires immediate surgery. Surgery may involve
- untwisting the colon
- dividing the bands of tissue that obstruct the small bowel
- repositioning the small bowel and colon
- removing the appendix
Surgery to relieve the blockage of the small bowel is usually successful and allows the digestive system to function normally.
