Difficult defecation in constipated patients: Diagnosis by minimally invasive diagnostic tests

Background and aims: Defecation Disorders (DD) are a frequent cause of refractory chronic constipation. DD diagnosis requires anorectal physiology testing. Our aim was to evaluate the accuracy and Odds Ratio (OR) of a straining question (SQ) and a digital rectal examination (DRE) augmented by abdomen palpation on predicting a DD diagnosis in refractory CC patients.

Methods: Two hundred and thirty-eight constipated patients were enrolled. Patients underwent SQ, augmented DRE and balloon evacuation test before entering the study and after a 30-day fiber/laxative trial. All patients underwent anorectal manometry. OR and accuracy were calculated for SQ and augmented DRE for both dyssynergic defecation and inadequate propulsion.

Results: "Anal Muscles" response was associated to both dyssynergic defecation and inadequate propulsion, with an OR of 13.6 and 5.85 and an accuracy of 78.5% and 66.4%, respectively. "Failed anal relaxation" on augmented DRE was associated with dyssynergic defecation, with an OR of 21.4 and an accuracy of 73.1%. "Failed abdominal contraction" on augmented DRE was associated with inadequate propulsion with an OR >100 and an accuracy of 97.1%.

Conclusions: Our data support screening constipated patients for DD by SQ and augmented DRE to improve management and appropriateness of referral to biofeedback.