Endometriosis is a condition where tissue similar to the lining of the uterus (the endometrial stroma and glands, which should only be located inside the uterus) is found elsewhere in the body. This can only be diagnosed via laparoscopy with "visual inspection".
Studies indicate that women with endometriosis take longer to conceive (become pregnant) and are less likely to conceive than women in general. It is important to remember that having endometriosis does not automatically mean that you will never have children.
Surgery for endometriosis-related infertility aims to remove any endometriosis and adhesions present. If the endometriosis has damaged any organs, or resulted in them being stuck down in abnormal positions, the surgery will also try to repair the damage and restore the anatomy of the organs to as close as possible to their normal positioning.