Table 2.

Mechanism of pain associated with endometriosis

A	Pain due to endometriotic lesions
1	Peritoneal lesions induce inflammatory reactions and secrete prostaglandins, cytokines, histamine and kinin that cause pain.
2	Deep infiltrating endometriosis destroys tissues and nerves.
3	Ruptured chocolate cysts may irritate peritoneum.
B	Scar and fibrosis, secondary lesions
1	Scar, fibrosis, traction, and adhesion may reduce mobility of organs. Pain may occur during movement or ovulation.
2	Adhesion of bowel may cause defecation pain or dyschezia.
3	Retroverted uterus due to adhesion, severe adhesion of ovaries to Douglas pouch, and induration of sacral ligament may cause dyschezia.