Purpose: The aim of this study was to investigate neuropathologic changes in the colonic wall of patients with slow transit constipation using monoclonal antibodies raised against neurofilament.
Methods: In a prospective study, 227 patients with severe, long-standing constipation and intractable defection disorders were analyzed according to a standard protocol. Slow transit constipation was diagnosed in 65 patients (29 percent). Forty-three patients (7 men and 36 women; mean age, 46 years; range, 16-76 years) underwent a partial (n = 20) or subtotal (n = 23) colectomy. In 39 patients (5 with megacolon and 34 with normal-sized colon) the cause of their constipation remained unexplained (idiopathic slow transit constipation). All resected colon specimens were investigated with the monoclonal antineurofilament antibody NF2F11 and compared with those of 20 control patients.
Results: In all controls the myenteric plexus revealed a moderate and diffuse axonal staining. In 29 of 39 patients with "idiopathic" slow transit constipation, the apparently normal axon bundles in the myenteric plexus stained markedly less than normal or failed to stain at all with the monoclonal antibody. In 17 patients this reduced or absent neurofilament expression was found along the entire length of the colon, whereas in 12 patients only a portion of the colon was affected.
Conclusion: These findings indicate that a visceral neuropathy seems to be present in the majority of patients with severe, so-called idiopathic slow transit constipation.