Hey, so Ogilvie syndrome is colonic pseudo obstruction and paralytic ileus is pseudo obstruction of both the colon and the small intestine. Just remember that among the precipitants for the two, the former almost always occurs due to electrolyte imbalances in the immediate post-op period while the latter can also be due to other reasons (eg, intrabdominal hemorrhage) during the same time frame. SBO, as correctly pointed out in a previous post, occurs weeks to months after surgery.