The present invention discloses a method of treating an individual having irritable bowel syndrome or a related disorder, comprising the step of administering to said individual a pharmacologically effective dose of a luminally active anti-inflammatory or immunosuppressive compound with minimal or no systemic side effects. Further provided is a method of inhibiting the onset of symptoms of irritable bowel syndrome or a related disorder in an individual in need of such treatment, comprising the step of administering to the individual a prophylactically effective dose of a luminally active anti-inflammatory or immunosuppressive compound with minimal or no systemic side effects.