Post-surgical colorectal leaks and fistulas are severe complications that dramatically increase morbidity and mortality. Over-the-scope clip (OTSC) application, introduced in clinical practice in 2007, represents an innovative technique to seal the visceral wall for acute and chronic colorectal post-surgical leaks and fistula management. Endoscopic closure of colorectal post-surgical leaks and fistulas with OTSC is a safe technique that accomplishes a high success rate in both acute and chronic cases, including rectovaginal, rectovesical, and colocutaneous fistulas. Overall success rate is higher than 80%, as reported in the literature, in both acute and chronic situations. No OTSC-related complications have been described in the lower gastrointestinal tract so far. This article is part of an expert video encyclopedia.