An anastomotic leak following restoration of intestinal continuity is one of the most dreaded complications following gastrointestinal tract surgery. Disruption of the colorectal anastomosis is a difficult complication that leads to significant morbidity and, at times, death. Since the inception of intestinal anastomoses, surgeons have looked for various methods to try and predict its occurrence prior to the patient's leaving the operating room. Several techniques have evolved to comfort the surgeon that his or her anastomosis is secure from disruption, but mostly center on integrating the anastomosis with an isotonic sodium chloride solution, 10% povidone-iodine, or air insufflation. Although most surgeons today will rely on the instillation of air via the colonoscope to test the anastomosis, data supporting its use as a method of ensuring anastomotic integrity is, at best, inconclusive. This large study of left-sided colorectal anastomoses reveals that, indeed, anastomotic leak testing is beneficial and that an airtight anastomosis may be a reliable indicator of anastomotic integrity. Three very important conclusions are brought to the forefront. First, an airtight anastomosis does not guarantee that anastomotic disruption will not occur postoperatively. Second, primary repair of a colorectal anastomosis that does not subsequently leak on testing also does not guarantee a subsequent postoperative anastomotic leak. Third, these data seem to suggest that an initial positive anastomotic leak test that either repair with fecal diversion or resecting the initial anastomosis and performing a new colorectal anastomosis will offer the best chance of not encountering a postoperative leak. Although the data presented did not comment on details such as the circumferential nature of the initial leak, the percentage of the anastomosis that had to be primarily repaired (perhaps number of 3-0 silks used), or the preexisting comorbidities of these patients related to risk of an anastomotic leak, the data from this article proposes an algorithmic approach to the results of the intraoperative anastomotic leak testing following colorectal resection and directs the surgeon to the need to repair, re-resect, or divert.