Long-term Safety With Vedolizumab Intravenous (IV) in Pediatric Participants With Ulcerative Colitis (UC) or Crohn's Disease (CD)

Inclusion Criteria:

1. Is male or female with UC or CD and was between 2 to 17 years, inclusive, at the
time of randomization for Study MLN0002-2003.

(Note: A participant remains eligible to participate in this study after they reach
18 years of age if they continue to meet the inclusion criteria and do not meet any
exclusion criteria.)

2. Has completed Study MLN0002-2003 and, at Week 22, achieved clinical response as
defined by a reduction of partial Mayo score of >=2 points and >=25% from Baseline,
or a reduction of the Paediatric Ulcerative Colitis Activity Index (PUCAI) of >=20
points from baseline for participants with UC; or a reduction of the CDAI as defined
by a >=70-point decrease from Baseline or a decrease of Pediatric Crohn's Disease
Activity Index (PCDAI) of >=15 points for participants with CD.

3. May be receiving a therapeutic dose of the following drugs:

- Oral 5-aminosalicylic acid (5-ASA) compounds.

- Oral corticosteroid therapy (prednisone or equivalent steroid at a dose less
than or equal to [<=] 50 milligram per day [mg/day]) provided the participant
was receiving this medication during prior participation in MLN0002-2003.

- Topical (rectal) treatment with 5-ASA or corticosteroids.

- Probiotics (example, Saccharomyces boulardii).

- Antidiarrheals (example, loperamide, diphenoxylate with atropine) for control
of chronic diarrhea.

- Antibiotics used for the treatment of CD (i.e., ciprofloxacin, metronidazole).

- Azathioprine (AZA) or 6-mercaptopurine (6-MP) or methotrexate (MTX), provided
the participant was receiving this medication during prior participation in
MLN0002-2003.

4. The participant's vaccinations are up to date as per inclusion criteria number 10 in
MLN0002-2003.

Exclusion Criteria:

1. Is female and is lactating or pregnant.

2. Has hypersensitivity or allergies to vedolizumab or any of its excipients.

3. Has withdrawn from Study MLN0002-2003.

4. Has developed any new unstable or uncontrolled cardiovascular, heart failure
moderate to severe (New York Class Association III or IV), pulmonary, hepatic,
renal, gastrointestinal (GI), genitourinary, hematological, coagulation,
immunological, endocrine/metabolic, neurological, or other medical disorder that, in
the opinion of the investigator, would confound the study results or compromise
participant safety.

5. Has a positive progressive multifocal leukoencephalopathy (PML) subjective symptom
checklist prior to the administration of the first dose of study drug.

6. Currently requires major surgical intervention for UC or CD (example, bowel
resection), or is anticipated to require major surgical intervention for UC or CD
during the study.

7. Has other serious comorbidities that will limit his or her ability to complete the
study.