A 39-year-old woman with Lynch syndrome and a previous diagnosis of sigmoid colon adenocarcinoma underwent total laparoscopic colectomy with ileorectal anastomosis and protective ileostomy. During planning for ileostomy reversal, colonoscopy revealed a complete stenosis of the ileorectal anastomosis, which was confirmed by contrast-enhanced computed tomography using rectal contrast. Given these findings, endoscopic management using a Rendez-vous technique was proposed. A gastroscope was introduced through the ileostomy, revealing a fixed angulation approximately 30 cm from the stoma, which prevented further advancement of the scope. At this site, a bulging area corresponding to the previous anastomosis was identified. A small central incision was made at the presumed location of the anastomotic lumen using a micro-knife. A guidewire was advanced through the incision, followed by contrast injection, which delineated the pre-anastomotic ileal loop under fluoroscopic guidance. A hydrostatic balloon was then advanced over the guidewire through the newly created orifice and dilation was performed up to 15 mm. After this initial dilation, both afferent and efferent ileal limbs—consistent with a side-to-end anastomosis—could be traversed endoscopically without complications. Two weeks later, a repeat colonoscopy performed via the anal route demonstrated a patent anastomosis with an approximate diameter of 7 mm. A second balloon dilation was performed, achieving a diameter of 18 mm. With complete resolution of the stenosis confirmed endoscopically, the patient was subsequently referred for ileostomy closure. This case illustrates the efficacy and safety of endoscopic recanalization for complete anastomotic obstructions, even in complex postoperative anatomy such as that associated with total colectomy for hereditary colorectal cancer syndromes. The combined use of the Rendez-vous approach, micro-knife incision, fluoroscopic guidance, and sequential balloon dilations allowed successful restoration of bowel continuity while avoiding surgical reintervention.