The design of an early mobile health application (app) prototype to manage interstitial cystitis/painful bladder syndrome, a chronic condition characterized by recurrent pain/discomfort in the bladder and pelvic floor, is described. The purpose of this app prototype is to help people who have IC/PBS manage and learn what triggers their symptoms. Another aim of this research was to provide an example of how sex and gender could be included into the design of a health information system. Based on a literature search of common symptoms and challenges faced by people living with IC/PBS, the researcher created an app prototype design including many features: resources for relaxation, mental health, intimacy, pregnancy, and daily life; reminders for appointments, and medication; logs for diet, activity, sleep, pain, menstruation; and a link to a public washroom locator. This prototype will later undergo usability and content evaluation.