Biofeedback efficacy for outlet dysfunction constipation: Clinical outcomes and predictors of response by a limited approach

BACKGROUND: Functional defecation disorders (FDD) are a common etiology of refractory chronic constipation (CC). FDD diagnosis (dyssynergic defecation [DD] and inadequate defecatory propulsion [IDP]), requires diagnostic tests including anorectal manometry (ARM) and balloon expulsion test (BET). Biofeedback (BF) is the treatment of choice for DD. The aims of our study were to evaluate: the outcome of BF in a group of constipated patients with defecatory disorders of any etiology; the efficacy of two simple diagnostic tools in predicting BF outcome in the short-term. METHODS: One hundred and thirty-one refractory CC patients failing the BET underwent BF therapy. Before BF, all patients underwent the following: ARM. Straining questionnaire. The answers were: "belly muscles"; "anal muscles"; "both"; "Don't know/No answer." Digital rectal examination augmented by abdominal palpation on straining (augmented-DRE). The BF therapist was blinded to ARM, straining questionnaire, and augmented-DRE results. KEY RESULTS: Eighty-one patients responded to BF. Gender, age, and IBS-C showed no significant impact on BF response. Both DD and IDP responded equally to BF, while the rate of response in patients with isolated structural pelvic floor abnormalities was lower (p < 0.001). The answer "anal muscles" to straining questionnaire showed a strong association with BF response (p < 0.001). A lack in abdominal contraction and in anal relaxation on augmented-DRE were strongly associated with BF response (p < 0.01). Absence of manual maneuvers to facilitate defecation was associated with BF response (p < 0.001). CONCLUSIONS & INFERENCES: BF is the therapy of choice for refractory constipation due to FDD of any etiology, inducing both clinical and anorectal physiology improvement in the short term. Comorbid IBS-C did not affect outcome while symptomatic isolated pelvic floor abnormalities appeared refractory to behavior treatment. The straining questionnaire and augmented-DRE outcomes showed a strong correlation with BF response and can be implemented in clinical practice to improve the management of constipated patients by prompting early referral to BF.