A Study of Guselkumab in Pediatric Participants With Moderately to Severely Active Ulcerative Colitis

Inclusion Criteria:

• Weight greater than or equal to (>=) 10 kilogram (kg) at the time of consent forscreening

• A pathology report to support a documented diagnosis of Ulcerative Colitis (UC) mustbe available in the source documents. There is no maximum duration for which aparticipant needs to be diagnosed with UC. If the pathology report to support adocumented diagnosis of UC is not available in the source documents, the screeningendoscopy with biopsies (obtained within 3 weeks before first study interventionadministration) needs to support the diagnosis of UC.

• Moderately to severely active UC, defined by a baseline modified Mayo (withoutphysician's global assessment) score of 5 through 9 inclusive, with a screening Mayoendoscopy subscore >= 2 as determined by a central review of the video of theendoscopy

• Medically stable based on physical examination, medical history, and vital signs,performed at screening. Any abnormalities must be consistent with the underlyingillness in the study population and this determination must be recorded in theparticipant's source documents and acknowledged by the investigator

• Participants must have had an inadequate response and/or intolerance to biologictherapy and/or conventional therapies or be dependent upon corticosteroids

Exclusion Criteria:

• Have UC limited to the rectum only or to less than (<) 20 centimeter of the colon

• Presence of a stoma

• Has had any kind of bowel resection within 6 months or any other intra-abdominalsurgery within 3 months of baseline

• Have severe colitis or have evidence of Crohn's Disease (CD)