The value of a non-invasive bladder sensitivity paradigm in chronic pelvic pain.

Abstract: We explore bladder sensitivity profiles in females with chronic pelvic pain, using a non-invasive bladder sensitivity paradigm. We aim to determine how profiles differ between groups defined by symptoms; groups defined by diagnoses; and understanding how bladder sensitivity relates to clinical symptoms. A previously developed non-invasive bladder sensitivity paradigm will be used, which assesses pain and urgency ratings during physiological bladder filling, time to reach descriptive sensations, and volume voided at the paradigm end. Our cohort comprised individuals with (pain + bladder) and without (pain only) overt bladder symptoms and pain-free/bladder-symptom-free controls; within both pain groups were participants with and without endometriosis. In addition, questionnaires were completed, which included bladder- and bowel-related symptoms. Participants with pain + bladder symptoms had significantly greater pain intensity scores throughout the paradigm compared with controls. When looking at underlying diagnoses, the only significant difference between those with bladder symptoms, with and without endometriosis, was in the volume voided at the end of the paradigm. We found correlations between pain ratings during the paradigm and gastrointestinal symptom scores from questionnaires. We found that the paradigm can distinguish between those with overt bladder symptoms and controls. It also appears to potentially identify a group of individuals with 'silent' bladder symptoms. It is currently unclear whether those with 'silent' symptoms go on to develop overt symptoms. Overall, our study highlights the need to explore bladder sensitivity in individuals with any form of chronic pelvic pain, as comorbidity is common and 'silent' symptoms are not well understood. Lay summary: This study explored bladder sensitivity in people with chronic pelvic pain, with and without bladder symptoms, compared with a control group of people without pain. We wanted to explore pain and urgency when people drank water and how this differed in people with different symptoms and diagnoses. We asked people to drink 20 fl oz of water and give ratings of pain and urgency throughout, as well as when they felt certain sensations. We found differences between those with overt bladder symptoms and the control group, with those with overt bladder symptoms experiencing greater pain. We did not find differences between different diagnoses (e.g. those with and without endometriosis) in pain or urgency ratings. This study highlights the need to explore bladder sensitivity in individuals with any form of chronic pelvic pain.