PARADOX study

You may be able to join if

• In order to be eligible to participate in this study, a subject enrolled in the treatment groups must meet all of the following criteria: All patients in treatment groups: 1. Documented diagnosis of UC ≥ 4 months prior to entry into the study, confirmed with endoscopy and pathology results available in the source documents 2. Moderately to severely active UC as defined by a total MAYO score of ≥ 5 and a MAYO ES of ≥ 2 determined within 7 days of starting HBOT treatment 3. Subjects must have failed or be intolerant (discontinued the medication due to an adverse event as determined by the investigator) of the following treatments: a. Oral corticosteroids b. Azathioprine or 6-mercaptopurine c. Anti-TNF therapy: infliximab, adalimumab or golimumab d. vedolizumab e. Current treatment with ustekinumab (or another p19 inhibitor in a clinical trial) or small-molecule therapy (e.g., tofacitinib) 4. Current treatment with a stable dose of ustekinumab or tofacitinib (>12 weeks of stable dose and interval of ustekinumab and >6 weeks of tofacitinib) 5. Age 16 or older 6. Approved for compassionate use of hyperbaric oxygen therapy by the treating physician and the health insurance company 7. In the opinion of the investigator, the subject is capable of understanding and complying with protocol requirements. 8. The subject signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures. 9. Male or non-pregnant, non-lactating females. Females of child bearing potential must have a negative serum pregnancy test prior to randomization, and must use a hormonal (oral, implantable or injectable) or barrier method of birth control throughout week 26. Females unable to bear children must have documentation of such in the source records (i.e., tubal ligation, hysterectomy, or post-menopausal [defined as a minimum of one year since the last menstrual period]).