What is Intestinal Malrotation?

Intestinal malrotation is a rare congenital anomaly, or birth defect, that occurs when the intestines do not properly rotate during embryonic development. During typical embryonic development, the gastrointestinal tract forms outside the abdomen and then makes a 270 degree rotation into its final resting position in the abdomen. Gut rotational anomalies, including intestinal malrotation, occur when the bowels fail to rotate the full 270 degrees and remain in the wrong anatomical position.

Individuals with intestinal malrotation also typically develop bands of abnormal tissue, called Ladd’s bands, which attach the first part of the small intestine called the duodenum to the large intestine or colon. This can cause feeding difficulties with little room for food to pass through.

While intestinal malrotation refers to the abnormal anatomical position of the intestines, this places an individual at higher risk for volvulus. Volvulus is a medical emergency where the intestines twist, which cuts off blood supply to the bowel. This can result in the damage or loss of bowel tissue, which can be fatal or result in short gut syndrome.

Simplistic illustration of normal anatomy compared to intestinal malrotation and volvulus. There are many anatomical variations of malrotation not pictured.

What are the symptoms of intestinal malrotation?

The symptoms of intestinal malrotation vary from person to person. Some individuals with malrotation may be asymptomatic. Others experience a wide range of variable symptoms which include:

Vomiting which can be bilious (green or fluorescent yellow) or nonbilious
Abdominal pain or tenderness
Swollen and/or rigid abdomen
Poor weight gain / failure to thrive
Food intolerance or malabsorption
Constipation or diarrhea
Sepsis/shock

Is intestinal malrotation rare?

The incidence or rate of occurrence remains unclear. It is estimated that 1 in 4,000 – 6,000 individuals have symptomatic intestinal malrotation. The majority of cases of symptomatic malrotation are diagnosed in neonates or infants, although individuals can be diagnosed with malrotation at any age. More research is needed to understand the epidemiology of intestinal malroation.

How is intestinal malrotation diagnosed?

The Upper Gastrointestinal series (Upper GI series) remains the gold standard diagnostic test for intestinal malrotation. This barium swallow or study involves a series of x-rays after the patient drinks a liquid contrast that contains barium sulfate that is visible on x-ray. Intestinal malrotation is diagnosed when the duodenum does not cross the midline. Diagnoses can sometimes be made through ultrasonography (ultrasound), computed tomography (CT), or exploratory laparotomy (surgical procedure).

How is intestinal malrotation treated?

The standard treatment for intestinal malrotation is a surgical procedure called the Ladd procedure. In this procedure, the bowels are untwisted (if needed), the Ladds bands are divided, the base of the mesentery is widened to minimize the risk of volvulus, and the bowels are placed in a position of nonrotation with the small bowel on the right and colon on the left side of the abdomen. Some individuals will need a bowel resection (bowel removed) if the tissue has been damaged.

After the Ladd procedure, the intestinal anatomy is not returned to a normally rotated position. There is now a novel Gut Malrotation Correction procedure that involves completing the 270 degree rotation of the intestines and fixation of the gut into the correct anatomical position.

What outcomes are expected?

The Ladd procedure was once thought to resolve many of the symptoms individuals with intestinal malrotation experience. However, more recent evidence suggests that the majority of individuals with malrotation continue to experience varying levels of gastrointestinal symptoms even after surgical treatment, and some require additional surgical procedures. Common ongoing symptoms include vomiting, abdominal pain and distension, constipation, diarrhea, gastroesophageal reflux disease (GERD), and other disorders of gut brain interaction. The Ladd procedure minimizes the risk of volvulus but does not eliminate the risk, and there is a risk of bowel obstructions due to adhesions that form after surgical procedures. More research is needed to better understand the various outcomes for individuals with intestinal malrotation.