Clinical utility of colonic manometry in slow transit constipation

Background The clinical significance of colorectal sensorimotor evaluation in patients with slow transit constipation (STC) is unclear. We investigated whether colonic manometric evaluation is useful for characterizing colonic sensorimotor dysfunction and for guiding therapy in STC. Methods 24-h ambulatory colonic manometry was performed in 80 patients (70 females) with STC by placing a six sensor solid-state probe, along with assessment of colonic sensation with barostat. Anorectal manometry was also performed. Manometrically, patients were categorized as having colonic neuropathy or myopathy based on gastrocolonic response, waking response and high amplitude propagated contractions (HAPC); and based on colonic sensation, as colonic hyposensitivity or hypersensitivity. Clinical response to pharmacological, biofeedback, and surgical treatment was assessed at 1year and correlated with manometric findings. Key Results Forty seven (59%) patients who had abnormal colonic manometry, with features suggestive of neuropathy (26%), and myopathy (33%); 41% had normal colonic manometry. Patients who had abnormal colonic sensation were 74% and 61% had overlapping dyssynergic defecation. Patients with neuropathy were more likely to have colonic hyposensitivity. Sixty-four percent of patients with colonic myopathy or normal manometry improved with medical/biofeedback therapy when compared to 15% with colonic neuropathy (P<0.01). Selected patients with colonic neuropathy had excellent response to surgery, but many developed bacterial overgrowth. Conclusions & Inferences Colonic manometry demonstrates significant colonic sensorimotor dysfunction in STC patients and reveals considerable pathophysiological heterogeneity. It can be useful for characterizing the underlying pathophysiology and for guiding clinical management in STC, especially surgery.