Ogilvie Syndrome can fool you: the colon looks obstructed, the belly is huge, but there’s no mechanical blockage. In this episode of Surgery Shelf Prep, Chris and Mars break down Acute Colonic Pseudo-Obstruction with the exact shelf-style framework you need—classic patient scenarios, key imaging findings, critical cecal diameter cutoffs, and the stepwise treatment algorithm from conservative management to neostigmine, colonoscopic decompression, and when to rush to surgery. We also cover the most testable traps, including how to quickly distinguish Ogilvie from ileus, sigmoid volvulus, and toxic megacolon.