An Observational Prospective Long-term Exposure Registry of Adult Patients With Moderate-to-Severe Ulcerative Colitis

Inclusion Criteria: * Have moderate-to-severe ulcerative colitis of at least 3 months' duration prior to enrollment, confirmed by endoscopy at any time in the past * For enrollment into the Simponi-exposed cohort meets one of the following: 1. The participant is currently receiving Simponi ,or 2. The participant is continuing to receive Simponi after participation in an ulcerative colitis study, or 3. The participant is scheduled to receive Simponi within 30 days after enrollment * For Thiopurine cohort: 1. The participant is currently receiving thiopurines, having received at least 12 consecutive weeks of therapy prior to registry entry 2. Participant must not be receiving other approved biologic agents, including Simponi, or any investigational agents at enrollment 3. Participant may have received biologics other than Simponi or investigational agents prior to enrollment Exclusion Criteria: * Participants who cannot be treated with Simponi or thiopurines * Participants with a previous diagnosis of lymphoma or hematologic malignancy at any time prior to enrollment * Participants currently receiving an investigational or biologic agent other than Simponi * Participants with any condition for which, in the opinion of the investigator, participation in the registry would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments