Visceral pain: inclusion criteria, assessment and pain outcomes

Visceral pain is commonly associated with other symptoms, such as nausea, diarrhea or urinary frequency. These associated symptoms increase the negative impact of the pain on quality of life and make it hard to select patient-relevant primary outcome measures for clinical trials. Visceral pain in women is frequently influenced by the menstrual cycle but even in men “flares” in pain are common and thus it is essential that the appropriate time frame is chosen over which to assess outcomes in order to truly determine if a treatment is beneficial. Irritable bowel syndrome (IBS), Interstitial cystitis/bladder pain syndrome (IC/BPS) and endometriosis-associated pain syndrome will be used as examples of visceral pain conditions to illustrate these points.