What Is Radiation-Induced Colitis?
Radiation-induced colitis is a chronic inflammatory condition of the large intestine that develops as a complication of radiotherapy to the pelvis or abdomen, most commonly following treatment for rectal, prostate, cervical or bladder cancer. In some cases, the small intestine is also affected, in which case the term radiation-induced enteritis is used.
Its onset may be significantly delayed, appearing months or even up to a decade after radiotherapy. This delay can make it difficult to establish the connection with the patient’s previous treatment.
Clinical symptoms vary and may include diarrhoea, haematochezia, abdominal pain, tenesmus, faecal incontinence and, in more severe cases, rectovaginal or enterocutaneous fistulas. Quality of life may be disproportionately affected, particularly in patients who have otherwise completed their cancer treatment successfully.
Pathology of Radiation-Induced Colitis
The pathology of radiation-induced colitis reflects the typical progression of radiation injury: vascular depletion, mucosal hypoxia, chronic inflammation and fibrotic degeneration.
The rectal mucosa may develop telangiectasia, ulceration and extensive fibrosis, all of which compromise the normal structure and function of the bowel.
A particularly important aspect of this condition is its impact on both physical and psychosocial well-being. A person who has overcome cancer may then face chronic bowel dysfunction that limits social activity, affects their ability to work and places a considerable psychological burden on them.
The management of these complications is therefore an integral part of comprehensive oncological care.
Clinical Studies
Clinical studies evaluating the use of hyperbaric oxygen therapy in patients with radiation-induced colitis and proctitis have reported high response rates, with reductions in haematochezia, improved bowel frequency and relief from pain. The Undersea and Hyperbaric Medical Society (UHMS) recognises radiation-induced proctitis and colitis as approved indications.
The mechanism of action follows the established model: restoration of mucosal oxygenation, stimulation of neovascularisation, reduction of chronic inflammation and repair of the mucosal architecture.
Restoring the blood supply to the ischaemic mucosa appears to partially reverse the structural changes responsible for the symptoms.
The Role of Hyperbaric Oxygen Therapy
In radiation-induced colitis, hyperbaric oxygen therapy addresses the underlying pathology rather than merely controlling the symptoms. This approach distinguishes it from conventional interventions, which are primarily aimed at symptomatic management.
Each session delivers high concentrations of oxygen to the ischaemic mucosa, reactivating its biological capacity for repair. Previously inactive cells are stimulated, new capillaries form and the structural integrity of the bowel gradually improves.
A typical treatment course consists of 30 to 40 sessions and is planned in coordination with the gastroenterologist and oncologist.