Review article: gender-related differences in functional gastrointestinal disorders

Many functional gastrointestinal disorders and other chronic Visceral pain disorders such as interstitial cystitis and chronic pelvic pain are more co mmon in women than in men. In irritable bowel syndrome (IBS) there is a 2:1 female to male ratio in prevalence of symptoms in community samples, Femal e irritable bowel syndrome patients are more likely to be constipated, comp lain of abdominal distension and of certain extracolonic symptoms. While animal studies have clearly demonstrated gender-related differences i n pain perception and antinociceptive mechanisms, unequivocal evidence for gender-related differences in human pain perception or modulation has only been provided recently. Gender-related differences may be related to consta nt differences in the physiology of pain perception, such as structural or functional differences in the visceral afferent pathways involved in pain t ransmission or modulation, and/or they may be related to fluctuations in fe male sex hormones. Preliminary evidence suggests that female irritable bowel syndrome patients show specific perceptual alterations in regards to rectosigmoid balloon di stension and that they show differences in regional brain activation measur ed by positron emission tomography. This preliminary evidence suggests that gender-related differences in symptoms and in the perceptual responses to visceral stimuli exist in IBS patients and can be detected using specific s timulation paradigms and neuroimaging techniques.