DIFFERENT PHENOTYPES OF CHRONIC CONSTIPATION IN MALES AND FEMALES

INTRODUCTION: Patients with chronic constipation exhibit symptoms and motility abnormalities that occur in combinations, but the nature of these combinations has not been characterized. METHODS: We calculated prevalences of combinations of symptoms (abdominal pain, infrequent defecation, incomplete evacuation, straining), abnormal motility test results (prolonged colonic transit time, low anal basal pressure, low anal squeeze pressure, poor rectal sensation, absent balloon expulsion), or both using data from 75 females and 91 males with chronic constipation. We calculated the Cluster Factor as observed prevalence of a combination of symptoms, abnormal test results or both divided by the prevalence of the combination due to chance. We calculated the conditional probabilities of combinations of symptoms, abnormal motility test results or both given the prevalence of other members of the same combination. RESULTS: Combinations of symptoms alone or abnormal motility test results alone in both males and females, and for combinations of symptoms plus abnormal motility test results in females, failed to cluster together beyond that attributable to chance alone. Males, however, showed significant clustering. Significant conditional probabilities with symptoms, and with symptoms plus abnormal motility test results was higher in males than females. Significant conditional probabilities with abnormal motility test results were not different between males and females. CONCLUSIONS: Gender-related differences in prevalences of combinations of symptoms and abnormal motility test results, of significant Cluster Factors, and of conditional probabilities indicate that chronic constipation in males reflects a fundamentally different disorder from that in females.