RATIONALE: Radiation therapy can cause long-term adverse effects. Hyperbaric oxygen therapy
may be effective in lessening gastrointestinal symptoms caused by radiation therapy given for
pelvic cancer. It is not yet known whether high-pressure oxygen is effective in treating
adverse effects caused by radiation therapy.

PURPOSE: This randomized phase III trial is studying hyperbaric oxygen therapy to see how
well it works in treating long-term gastrointestinal adverse effects caused by radiation
therapy in patients with pelvic cancer.