What is the most likely developmental anomaly in a patient with abdominal pain and distention on x-ray suggesting obstruction?

• A. Gastroschisis
• B. Malrotation
• C. Intestinal aganglionosis
• D. Situs inversus viscerum

Answer: (B)

In cases of abdominal pain and distention with radiological evidence suggesting obstruction, the most likely developmental anomaly is malrotation. Malrotation occurs when the intestines fail to properly rotate during fetal development, which can lead to an abnormal position of the bowel and an increased risk of volvulus (twisting of the intestine). This twisting can cause obstruction, resulting in abdominal pain and distention, which aligns with the symptoms described.

The anatomical changes associated with malrotation, specifically the failure of the normal rotation around the superior mesenteric artery, can lead to a compromised blood supply to the affected intestines and subsequent obstruction. Radiological findings, particularly those showing signs of bowel obstruction, would reinforce this diagnosis.

Other conditions such as gastroschisis, intestinal aganglionosis, and situs inversus viscerum have distinct presentations and complications. Gastroschisis typically presents with exposed bowel outside the abdominal cavity and does not primarily present as an obstruction due to malrotation. Intestinal aganglionosis, like in Hirschsprung's disease, often leads to constipation and bowel dilation, but the presentation of acute abdominal pain and obstruction is more closely linked to malrotation. Situs inversus viscerum involves a mirror image reversal of organs but is not