Normal Meconium Passing Was Noted (MCQ)

The formation of normal bowel in the embryo involves a rotation of elongated intestine into the abdominal cavity. The proximal small intestine develops a C-shaped contour, with the duodenum fixing to the left of the midline at the ligament of Treitz. The caecum undergoes counter-clockwise rotation to end up in the right lower abdomen. Incomplete rotation results in inadequate fixation of the intestinal mesentery. Bands may be formed which cause incomplete intestinal obstruction. If there is inadequate fixation of the small bowel, the intestine can twist on the axis of the superior mesenteric artery.

The presentation may be subtle (including intermittent episodes of vomiting in a baby otherwise feeding normally) or more obvious with signs of bowel obstruction or even life-threatening collapse. Episodes of bile-stained vomiting in infants should be taken seriously. There may be blood-stained stool.

Plain films may be normal or may show evidence of duodenal obstruction with a paucity of bowel gas through the rest of the abdomen

Air-fluid levels suggesting obstruction are not usual with malrotation. An airless abdomen is a sign of severe problems and usually indicates intestinal infarction. Upper intestinal contrast studies are reliable in localising the ligament of Treitz. There may be a typical corkscrew constriction of the third portion of the duodenum

Treatment is surgical, with correction of the malrotation of the colon and therefore prevention of a midgut volvulus. If a volvulus is suspected, an emergency laparotomy should be undertaken.