Early postoperative anastomotic obstruction after colorectal surgery rarely develops. Herein, we present a case of a 50-year-old healthy woman who had an early postoperative anastomotic obstruction which was revealed caused by a blood clot and successfully managed by endoscopic approach. The patient was discharged after laparoscopic anterior resection and visited the emergency department one day after because of abdominal pain. Computed tomography showed that the anastomosis site was obstructed with low-density material. Intraoperative endoscopy was performed under general anesthesia and blood clot filling the lumen were identified. As the scope was advanced to the blood clot with air inflation, the blood clot was evacuated. The anastomosis site could be obstructed by blot clot with mucous debris albeit it is a rare condition. An endoscopic approach seems to be the first option in the diagnosis and treatment of postoperative obstruction at the anastomosis site and it could prevent unnecessary laparotomy.