A volvulus is a twisting of the bowel on itself. It is one cause of intestinal obstruction.
Paralytic ileus is one of the major causes of obstruction in infants and children.
Mechanical obstruction occurs when movement of material through the intestines is physically blocked. If the obstruction blocks the blood supply to the intestine, the tissue may die, causing infection and gangrene. Risk factors are intestinal malignancy , Crohn's disease , hernia , and previous abdominal surgery.