Translational Research in Pelvic Pain

Inclusion Criteria: * Female, aged 18 - 50 years. * Participant is willing and able to give informed consent for participation in the study. * EAP/EABP/CON: previously enrolled in EndOX or BCE cohorts with consent to be contacted again. * EAP: Surgical diagnosis of endometriosis; at least one pelvic pain \>3/10. * EABP: Surgical diagnosis of endometriosis; at least one pelvic pain \>3/10; pain perceived by the patient as arising from the bladder AND from other area(s) of the pelvis; at least one urinary symptom (e.g. urge, frequency). * BPS: fulfil ESSIC criteria (Pelvic pain, pressure or discomfort for greater than 6 months, perceived to be related to the urinary bladder accompanied by at least one other urinary symptom like persistent urge to void or frequency). Exclusion Criteria: * Female participant who is pregnant, lactating or planning pregnancy during the course of the study. * Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial. * EAP: pain perceived by the patient as arising from the bladder; urinary symptoms (e.g. urge, frequency). * CON: previous diagnosis of endometriosis; pelvic pain or dysmenorrhoea (NRS\>3/10) * BPS: previous diagnosis of endometriosis. Additionally, for physiological testing: Exclusion: • Participants who have participated in another research trial involving an investigational product in the past 12 weeks. And for fMRI: Inclusion: • fMRI compatible. Exclusion: * Contraindication to fMRI scan i.e. metallic implants, stents, clips, weight greater than acceptable for local fMRI scanner etc. * Use of centrally acting drugs in the previous 3 months (e.g. anti-epileptics, anti-depressants, anxiolytics, gabapentin, pregabalin, duloxetine). N.B. Regular use of standard analgesics including opiates is not an exclusion criterion, however, women will be asked to refrain from taking such drugs for 8 hours prior to their brain scan if at all possible.