Distal Intestinal Obstruction Syndrome

  • Etiology: Complication of cystic fibrosis where lack of pancreatic enzymes in cystic fibrosis patient causes intestinal bowel contents to become thick and sticky and stool-like in distal and terminal ileum leading to a distal small bowel obstruction
  • Imaging AXR: Small bowel obstruction due to inspissated stool in distal ileum (small bowel stool sign)
  • Imaging CT: Small bowel obstruction due to inspissated stool in distal ileum (small bowel stool sign)
  • DDX:
  • Complications: Small bowel obstruction
  • Treatment: Water-soluble hyperosmolar contrast enema to reflux contrast into dilated small bowel loops above area of obstruction
  • Clinical: Appearance and treatment similar to that of uncomplicated meconium ileus and therefore this entity was formerly called meconium ileus equivalent

Radiology Cases of Distal Intestinal Obstruction Syndrome

AXR and barium enema of distal intestinal obstruction syndrome
AXR (left) shows a distal small bowel obstruction. Water-soluble contrast enema (right) shows the cecum flipped up into the left upper quadrant with the stool-filled terminal ileum outlined by contrast just beneath it.
AXR of distal intestinal obstruction syndrome / DIOS
AXR supine (above left) shows multiple dilated loops of small bowel with a stool-like mass in the mid-abdomen. AXR upright (above right) shows multiple air-fluid levels. AP image from an enema with high osmolar water soluble contrast (below) shows complete opacification of a normal appearing colon. The terminal ileum could not be refluxed and specifically the stool-like mass in the mid-abdomen could not be reached with contrast.

Radiology Cases of Distal Intestinal Obstruction Syndrome and Fatty Infiltration of the Liver and Acute Pancreatitis With Pseudocyst and Chronic Pancreatitis and Normal Appendix

CT of enlarged but normal appendix in cystic fibrosis
Axial CT with contrast of the abdomen (above left) shows a low density liver due to fatty infiltration and a low density pancreas with calcifications that has a round low density fluid collection near the pancreatic head. The appendix in the right lower quadrant posterior to the cecum is dilated in diameter up to 10 mm but has no periappendiceal inflammation (above right and below). There is stool mixed with air in the terminal ileum medial to the cecum (above right and below).