The participating surgeons and assistants from each site will be trained on the procedural use of NBI by Olympus and the coordinating center. A minimum of three cases of patients suspected to be positive for endometriosis will be watched by surgeons and coordinators from remaining sites. The training surgeon will perform the sweep through the quadrants of the pelvis. Each area will be viewed under white light. The training surgeon will ask the surgeons to identify suspicious areas that they would biopsy. Then the training surgeon will switch to NBI and once again ask the training surgeons to identify suspicious areas that they would biopsy. This will be done to ensure that all participating surgeons are able to identify suspicious areas under both imaging modalities to learn what potential endometrial lesions look like under NBI.