Biofeedback Therapy in Patients with Functional Evacuation Disorders

Biofeedback therapy has emerged as a useful adjunct for patients with functional evacuation disorders over the past decade. The goals of biofeedback retraining may vary and could depend on the underlying dysfunction. In patients with obstructive defecation, the goals are to relax the anal sphincter, improve rectoanal coordination, and improve sensory perception. Methods of biofeedback therapy varied widely between centers. However, no difference was described when EMG-based biofeedback was compared to manometry-based biofeedback, or when visual or auditory feedback was given. In regards to biofeedback adjuncts, including sensory retraining with either an intrarectal balloon, a portable home-training unit or both can be practicable. There are inconsistencies in the literature regarding the patient selection criteria for biofeedback treatment. The patient group is not homogeneous. Different case selection, different regimens and different methods of biofeedback may explain the variability in success rate. Quality research that would assist in predicting outcome is still lacking. Although no specific denominator could possibly be assigned to correctly predict the overall outcome of therapy, biofeedback is not successful in all patients with outlet obstructed constipation. Results with success rates is ranging from 8.3 percent to 100 percent. The treatment of constipation by biofeedback has been viewed with some skepticism as the low success rate may simply be a placebo effect. The majority of scepticism to therapeutic outcome are derived from entry criteria for treatment. Lower success rates have been described when entry criteria were broadened. Prebiofeedback clinical findings which are presupposed to prognostic relevance are age, gender, duration of symptoms and presence of rectal pain, lower motor neuron disease, and psychiatric problems. I feel strongly that informations about the predictive factors are vital to all physicians either performing or recommending biofeedback to their patients. If biofeedback could be undertaken according to specific criteria, we, colorectal surgeon will save a fruitless endeavour, one would expect more improvements in more patients. Additional well-designed controlled trials are needed to establish the clinical and physiologic factors.

Diagnosis and Management of Functional Evacuation Disorders

Over the last decade, anorectal physiologic investigations have emerged as a useful adjunct for patients with functional evacuation disorders. Through application of new sophisticated techniques and armamentarium, it has been possible to find more specific aspects of the colorectal function in patients with refractory defecation disorders. There are three groups of patient's with constipating symptoms. These patients have obstructed defecation, slow transit constipation, or a combination of both. Slow transit constipation is a severe disorder of colonic motility presenting predominantly in women. Obstructed defecation is a clinical problem frequently thought to be due to functional abnormalities of the pelvic floor leading to outlet obstruction. Defecation is an integrated process of colonic and rectal emptying, and has led to the realization that obstructed defecation is more complex than just a simple disorder of the pelvic floor muscles. Anorectal manometry establishes a quantitative measure of the pressure generated by the anal sphincters. Defecography is used to diagnose a variety of anatomical abnormalities of the rectum, including rectocele and intussusception. Tests of motor and sensory conduction in the pudendal nerves may indicate nerve damage, which accompanies chronic straining at stool. Colonic transit is an important variable and should always be considered in the assessment of patients with pelvic floor abnormalities, and measurement of colon transit by radioopaque markers or radioisotope techniques is an essential part of the workup of these patients. For the great majority of patients, dietary adjustment with increased fiber and liquid supplement can resolve these symptoms. Patients with slow transit colon can be expected to have a satisfactory outcome from colectomy and ileorectal anastomosis, but it is now appreciated that these patients form only a small proportion of those with chronic idiopathic constipation. Current management strategies for patients with obstructed defecation should be based on carefully identifying the underlying pathophysiological disorder and the use of conservative nonsurgical methods, including pelvic floor retraining (biofeedback) where appropriate. Surgical intervention should be limited to the very few patients with identifiable, surgically correctable causes of outlet obstruction.