In chronic pelvic pain, 61% will have painful bladder syndrome, 70% will have endometriosis, and 48% will have both. They do indeed seem to be evil twins often operating together.
nt J Surg. 2013;11(3):233-7.
The ‘evil twin syndrome’ in chronic pelvic pain: A systematic review of prevalence studies of bladder pain syndrome and endometriosis.
Tirlapur SA, Kuhrt K, Chaliha C, Ball E, Meads C, Khan KS. abstract here
Comment – does not seem to be any point in dealing with chronic pelvic pain without dealing with potentially both of these factors. Also in people with endometriosis or painful bladder syndrome, its evil pair needs to be sought out. MRI has superiority in diagnosing ovarian endometriosis, and transvaginal ultrasound for deep pelvic endometriosis.