Clinical presentation and characteristics of pelvic floor myofascial pain in patients presenting with constipation

Background Patients with pelvic floor myofascial pain (PFMP) have puborectalis tenderness on digital rectal examination (DRE). Little is known about its significance to anorectal function in patients presenting with constipation. Aim To characterize demographics, clinical characteristics, findings on anorectal manometry (ARM), diagnosis of rectal evacuation disorder (RED), colonic transit [normal (NTC) or slow (STC)], and imaging in constipated patients with PFMP and compare these features to constipation without PFMP. Methods We performed an electronic medical records review of patients with constipation evaluated by a single gastroenterologist between January 2008 and February 2019. Patients with PFMP were compared to controls with constipation but without PFMP (1:2 ratio). Key Results A total of 98 PFMP cases and 196 controls were identified. Constipated patients with PFMP were more likely to have RED [OR 7.59 (3.82-15.09), P < .01]; controls were more likely to have either NTC [OR 4.25 (1.45-12.42), P < .01] or STC [OR 3.57 (1.45-8.78), P < .01]. RED in patients with PFMP is supported by comparison to controls: On DRE, they had increased resting tone [OR 2.25 (1.33-3.83), P < .01] and paradoxical contraction of the puborectalis upon simulated evacuation [OR 3.41 (1.94-6.00), P < .01]; on ARM, they had higher maximum resting pressure (102.9 mmHg vs 90.7 mmHg, P < .01) and lower rectoanal pressure gradient (-39.4 mmHg vs -24.7 mmHg, P < .01). Conclusions/Inferences In constipated patients, PFMP is highly associated with RED. Its presence provides a valuable clue regarding the etiology of a patient's constipation; it should be assessed in all patients with constipation and should also be an additional target for management.