What Is Crohn’s Disease?
Crohn’s disease is a chronic inflammatory condition of the digestive tract that may affect any part of the gastrointestinal system, from the mouth to the anus. It most commonly involves the terminal ileum, the final part of the small intestine, and the colon.
It differs from ulcerative colitis because the inflammation is transmural, meaning that it extends through the entire thickness of the intestinal wall, and may be accompanied by characteristic granulomatous changes.
The condition follows a relapsing and remitting course, with periods of active disease, known as flare-ups, alternating with periods of remission. It can have a significant impact on quality of life.
The principal symptoms include abdominal pain, diarrhoea, which may contain blood, fatigue, weight loss, fever and extraintestinal manifestations such as arthritis, skin changes and eye disorders.
Approximately 30% to 40% of patients will require some form of surgery during their lifetime.
Characteristics of Crohn’s Disease
One of the less widely recognized but pathophysiologically important characteristics of Crohn’s disease is the local hypoxia that develops within the inflamed intestinal mucosa.
Extensive inflammation and disruption of the microcirculation create ischaemic conditions at mucosal level, aggravating tissue injury and impairing healing. This local hypoxia further intensifies the inflammatory response, creating a self-perpetuating cycle.
Perianal disease is also present in approximately 30% to 40% of patients and may involve fistulas, abscesses and fissures. It is often refractory and difficult to heal because of persistent inflammation and hypoxia within the affected tissue.
Perianal Crohn’s disease is one of the most challenging manifestations of the condition and one of the most promising emerging indications for hyperbaric oxygen therapy.
Clinical Studies
Clinical studies evaluating hyperbaric oxygen therapy in Crohn’s disease, particularly in perianal disease and refractory flare-ups, have reported significant improvements in disease activity indices, fistula healing and quality of life.
Case series involving refractory perianal Crohn’s disease have reported response rates above 60%, with some studies documenting complete fistula closure.
The proposed mechanism of action is multifactorial. It includes suppression of inflammatory cytokines such as TNF-α, IL-1β and IL-6, which drive the inflammatory response, restoration of oxygenation within the inflamed mucosa, improved healing of the intestinal wall and, specifically in fistulas, improvement of the biological conditions required for definitive closure.
This evidence places Crohn’s disease among the emerging indications for hyperbaric oxygen therapy with a clear biological rationale.
The Role of Hyperbaric Oxygen Therapy
In Crohn’s disease, hyperbaric oxygen therapy is used as an adjunctive intervention alongside and in support of primary gastroenterological treatment, whether this includes biologic agents, immunomodulators or corticosteroids.
It does not replace any of these treatments.
Restoring oxygenation within the inflamed mucosa helps interrupt the cycle of hypoxia and inflammation. Microcirculation improves, healing mechanisms are reactivated and inflammatory activity is reduced.
In perianal disease in particular, the combined anti-inflammatory and vascular effects create more favorable conditions for the closure of fistulas that have not responded to conventional treatment.
A typical treatment course consists of 20 to 40 sessions, planned in close collaboration with the gastroenterologist.