Distal intestinal obstruction syndrome (DIOS) involves blockage of the intestines by thickened stool and occurs in individuals with cystic fibrosis. DIOS was previously known as meconium ileus equivalent, a name which highlights its similarity to the intestinal obstruction seen in newborn infants with cystic fibrosis. DIOS tends to occur in older individuals with pancreatic insufficiency. Individuals with DIOS may be predisposed to constipation.
Symptoms of DIOS include crampy abdominal pain, vomiting, and a palpable mass in the abdomen. X-rays of the abdomen may reveal stool in the colon and air-fluid levels in the small bowel. Surgery is often required to relieve the obstruction. However, if there is no sign of bowel rupture, a more conservative approach may be attempted. Restricting oral intake, placement of a nasogastric tube for decompression of the stomach and proximal intestines, and administration of laxatives and enemas may resolve the obstruction without the need for surgery. Individuals prone to DIOS tend to be at risk for repeated episodes and often require maintenance therapy with pancreatic enzyme replacement and stool softeners.