Study to Assess Change in Disease Activity of Risankizumab Treatment in Japanese Participants With Moderate to Severe Ulcerative Colitis

Inclusion Criteria: * Participants with a diagnosis of moderate to severe Ulcerative Colitis (UC) commenced on Risankizumab (RZB) treatment prescribed as part of their routine clinical care at their clinical's discretion according to Japan approved label and treatment prescription recommendations/guidelines. * The decision to prescribe RZB is made prior to and independently of study participation. * Participants able to provide voluntary informed consent before any study-related activities or procedures (obtained/documented as per regulations). If the patient is under 18 years old, a patient's parent or legal guardian must be willing to give written informed consent. * Participants who can understand and communicate with the investigator and comply with the requirements of the study, including collection of PRO data using a smart device (i.e., mobile phone) and continued PRO data collection after cessation of RZB. * Participants without previous exposure to RZB. * Participants who are not currently participating in interventional research (not including non-interventional studies, PMOS, or registry participation). Exclusion Criteria: See Inclusion Criteria