OBJECTIVES: The purpose of this research was to develop an electronic daily sign and symptom diary, the Daily Ulcerative Colitis Scale (DUCS), including a patient reported outcomes (PRO) version for children 8-17 years and an observer reported outcomes (ObsRO) version for caregivers of children aged 5-10 years. METHODS: Open-ended one-on-one concept elicitation interviews were conducted with children aged 8-17 years with a documented history of mild to moderate ulcerative colitis confirmed by endoscopy, recruited from three clinical centers. The interviews focused on signs or symptoms associated with UC. In addition, five pediatric gastroenterologists and three nurses were interviewed about the pediatric UC signs/symptoms, and parent blogs on an active UC website were reviewed; the blogs included discussions on 26 children with UC.  Interview transcripts were developed, and a thematic analysis was conducted in which each new concept identified was coded using MaxQDA.  RESULTS: The concept elicitation interviews included 22 children in remission (six aged 8-12; 16 aged 13-17) and 10 children with active disease (four aged 8-12; six aged 13-17).  Information saturation (i.e., no new information reported in last patient interview) was achieved.  A core set of seven signs/symptoms in pediatric UC emerged: abdominal pain, blood in stool, frequent stools, diarrhea, stool urgency, nocturnal stools, and tiredness.  No substantial differences were observed across different ages, and descriptions were largely consistent across patients.  Even when in remission, children reported occasional symptoms.  The HCP interviews and blog data substantiated the interview findings; the HCPs confirmed that signs/symptoms of UC do not vary by age.  CONCLUSIONS: Children with UC were able to report their signs/symptoms associated with UC, and these data informed the development of two measures with phrasing that should resonate with the pediatric and caregiver populations.  These will be tested in cognitive debriefing interviews.