A Study of Long Term Persistency of Guselkumab in Adult Participants With Inflammatory Bowel Disease

Inclusion criteria: * Must be greater than or equal to (\>=) 18 years old * Must be eligible for biologic treatment and initiate guselkumab according to the approved indications as described in the current version of the summary of product characteristics (SmPC) of the drug. Decision to prescribe must solely be made by the treating physician. Enrolment must take place before or on the day of the first administration (but after treatment decision by physician) * Must have a confirmed diagnosis of moderate-to-severe Crohn's disease (CD) or Ulcerative Colitis (UC) recorded in their medical records * Participant has received the information note/given his/her oral agreement and has not objected to the collection of their data Exclusion criteria: * Contraindicated to guselkumab per the label * Is currently enrolled in an interventional clinical study * Has been previously exposed to interleukin (IL)-23 inhibitors, including Tremfya (guselkumab), Skyrizi (risankizumab) and Omvoh (mirikizumab). As an exception, participants with a prior history of Stelara (ustekinumab) and biosimilars exposure, may be included * History of more than 4 lines of advanced inflammatory bowel disease (IBD) therapy (biologics and/or small molecules)