Pseudo-obstruction of the colon, first described by Ogilvie1 in 1948 and usually referred to as Ogilvie's syndrome, is a specific variety of adynamic ileus. It is characterized by massive colonic dilatation with a clinical and radiologic findings very similar to mechanical large intestinal obstruction, except that there is no organic obstruction. The cecum is usually the site of greatest dilatation, though the whole large bowel may be involved, from the terminal ileum up to the rectosigmoid junction. The dilatation is rapidly progressive and, if untreated, may even cause cecal necrosis and perforation, with highly increased mortality rate. The syndrome has been associated with various metabolic and organic dysfunctions, and has been observed following gynecologic as well as simple surgical procedures; yet its occurrence has been rather uncommon. The followings are two case reports with this syndrome.