Best investigation to establish the diagnosis of endometriosis is:

Diagnostic laparoscopy is the gold standard for diagnosing endometriosis. Typical lesion: Powder burn/Gun shot lesions (black, dark brown, or bluish cysts with old hemorrhage surrounded by variable degree of fibrosis) Other non-typical findings could be: • Red implants • Serous or clear vesicles • White plaques/scarring • Yellowish brown discoloration of peritoneum • Sub ovarian adhesions • Presence of defects in the peritoneum (usually scarring overlying implants) is called as Allen masters syndrome. • Histological confirmation of laparoscopic impression is essential for diagnosis of endometriosis.