Slow transit constipation: a disorder of pelvic autonomic nerves?

Slow transit constipation (STC) is a severe motility disorder, which in the majority of cases is of unknown etiology. In some, symptoms arise de novo in childhood, but a proportion of patients present in later life, including after pelvic surgery or childbirth. Our aims were: (1) to describe our current knowledge of the anatomy and function of the pelvic autonomic nerves with respect to colonic motility (experimental and observational studies); (2) to discuss evidence for pelvic nerve injury in STC arising after pelvic surgery or childbirth; and (3), on the basis that such patients are clinically indistinguishable from patients with chronic idiopathic STC, to evaluate whether there is evidence that pelvic autonomic neuropathy has an etiologic role in patients with chronic idiopathic STC. The outcome was as follows: (1) The clear importance of the pelvic autonomic nerves in colonic motor function is documented. (2) While there is an association between pelvic surgery and childbirth, and the onset of STC, there is little direct anatomical evidence that pelvic denervation occurs in these patients. However the phenotype of these patients is similar to results of experimental and observational studies. (3) Clinical, physiological, and histological similarities exist between patients whose symptoms arose following pelvic intervention and those whose symptoms arise de novo (idiopathic). We further present evidence for possible pathogenetic mechanisms underlying pelvic autonomic neuropathy in chronic idiopathic STC.