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 Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 8  |  Issue : 1  |  Page : 4-9

Evaluating the efficacy of biofeedback for chronic constipation using the constipation severity instrument and constipation-related quality of life measure


1 Department of Surgery, Division of Colon and Rectal Surgery, Taipei Veterans General Hospital; Department of Surgery, National Yang-Ming University, Taipei, Taiwan
2 Department of Surgery, University of California, San Francisco, California, USA

Date of Web Publication12-Mar-2019

Correspondence Address:
Dr. Madhulika G Varma
Department of Surgery, University of California, San Francisco, 550 16th Street, 6th Floor, San Francisco, California 94158
USA
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/WJCS.WJCS_7_18

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  Abstract 


Background: Many studies have described using biofeedback to treat chronic constipation, but few reports have addressed its impact on quality of life (QOL). Objective: The aim was to evaluate the effect of biofeedback with a validated Constipation Severity Instrument (CSI) and Constipation-Related QOL (CRQOL) measure. Design: Prospectively collected data with retrospective analysis. Setting: Tertiary care academic center. Patients and Methods: Patients referred to the Center for Pelvic Physiology with chronic constipation and objective signs of pelvic floor dyssynergia, who received a complete course of biofeedback therapy and returned all of their questionnaires, were enrolled in the study. Questionnaires were given upon initial evaluation, immediately after the complete course of biofeedback, and 6 months later. Main Outcome Measures: Improvement of dyssynergia symptom and QOL by CSI and CRQOL. Sample Size: A total of 25 patients (20 females and 5 males) were included. Results: Overall, 75% of patients reported satisfactory symptom and QOL improvement. CSI total scores decreased after treatment (35.0 vs. 31.0, P = 0.06) and at 6-month follow-up (35.0 vs. 30.0, P = 0.05). Only the obstructive defecation (OD) subscale of CSI improved significantly after treatment (median 21.0 vs. 16.5, P < 0.01) and sustained to 6 months after therapy (median 21.0 vs. 18.5, P = 0.03). Statistically significant improvement was seen in the distress subscale of the CRQOL immediately after biofeedback (24.0 vs. 18.0, P = 0.02). Conclusions: This study demonstrated that the active effects of biofeedback in constipated patients were specific to OD symptoms and the distress subscale for QOL. CSI and CRQOL are both useful tools to evaluate the specific response of constipated patients after biofeedback therapy. Limitations: The study limitation was the small sample size due to difficulty in obtaining complete information in the enrolled patients.

Keywords: Biofeedback, constipation, obstructive defecation, outcome, quality of life


How to cite this article:
Lan YT, Jahan LG, Varma MG. Evaluating the efficacy of biofeedback for chronic constipation using the constipation severity instrument and constipation-related quality of life measure. World J Colorectal Surg 2019;8:4-9

How to cite this URL:
Lan YT, Jahan LG, Varma MG. Evaluating the efficacy of biofeedback for chronic constipation using the constipation severity instrument and constipation-related quality of life measure. World J Colorectal Surg [serial online] 2019 [cited 2019 Aug 18];8:4-9. Available from: http://www.wjcs.us.com/text.asp?2019/8/1/4/254038


  Introduction Top


Obstructed defecation syndrome, also known as pelvic floor dysfunction, anismus, or pelvic floor dyssynergia, is the most prevalent subtype of constipation. A paradoxical or inappropriate contraction of the puborectalis muscle and nonrelaxation of anal sphincter complex during an attempt at defecation is the known physiology of this syndrome.[1],[2] It accounts for about half of all cases of constipation.[3] Biofeedback therapy is the recommended treatment for these patients as there is no surgical correction for pelvic floor dyssynergia. Using visual and auditory feedback, patients can realize their unconscious maladaptive behavior of paradoxical contraction of the pelvic floor muscle during defecation. At the same time, they can learn how to gain a more efficient defecation by relaxing the sphincter and puborectalis muscle under the guidance of biofeedback therapists.[4] Furthermore, similar efficacy can be achieved by anal manometry sensors or electromyography (EMG) sensors.[4],[5],[6]

The reported success rate of biofeedback for constipation varies widely from 11% to 93%,[5] with mostly short-term results.[7] Because no actual anatomic or neurologic abnormality is found in these constipated patients, evaluating the quality of life (QOL) is extremely important in understanding patient outcome. Up to now, few reports have studied the success of biofeedback by investigating its effect on constipation-related QOL (CRQOL).[8],[9],[10] In addition, the active element that biofeedback provides to improve constipation-related symptoms and QOL is not known. The present study aims to evaluate the short-term and long-term efficacy of anorectal biofeedback for constipation by examining patients' satisfaction and perception of improvement along with their changes in physical symptoms, severity, and disease-specific and general QOL.


  Patients and Methods Top


The data were prospectively collected from patients who had chronic constipation and had been referred to the Center of Pelvic Physiology (CPP) at a tertiary care academic center. Patients who had been recommended to receive anorectal biofeedback at the CPP for treatment of their constipation were eligible to participate in the study. Constipation was considered present in participants who reported infrequent stools and those with difficulty of having a bowel movement in the past 6 months. Totally, 1239 patients diagnosed with chronic constipation were referred to CPP for evaluation from October 2005 to January 2014. Twenty-five patients who underwent a full course of biofeedback and agreed to participate in the study with written consent were enrolled into the study. The Committee on Human Research of the hospital approved the whole study procedures.

The demographic data, habitual bowel movements, and the past medical and surgical history of all the patients enrolled were recorded. Anorectal and digital rectal examinations, anorectal physiology evaluation including EMG, anorectal manometry, rectal sensation, and balloon expulsion test were performed. Bristol Stool Scale was used to measure stool consistency, and an additional category was added as score 0 when patients stated “I don't know – I always use laxatives.” The protocol of the anorectal physiology evaluation and questionnaires has been described in previous reports.[10],[11],[12]

Prior to the start of biofeedback, patients completed a baseline questionnaire package of standardized and validated self-report measures that assess constipation severity and CRQOL.[13],[14] This questionnaire package is part of a larger patient intake form already being administered to all new CPP patients as part of their routine care. Upon completion of all six sessions and again at 6-month follow-up, participants were asked to complete a posttreatment questionnaire package consisting of the same validated measures and a patient global satisfaction survey. Only patients who had fully completed all sessions of biofeedback were included in the study.

Biofeedback therapy

The standard care at the CPP consists of a six 1-hour sessions of biofeedback therapy, which is supervised by a trained and experienced nurse,[4] generally every other week, within a 12-week period. As part of these treatment sessions, counseling was provided in regard to dietary changes, dosage adjustment of laxatives, toilet habits, and pelvic stretch exercises. Detailed information about the purpose of biofeedback therapy and the physiology and anatomy regarding the pelvic floor were provided before therapy.[2] Patients lie at left lateral decubitus position, and an EMG sensor was used anorectally. Patients were instructed to watch tracing on the monitor during squeezing, straining, and relaxing of the anal sphincter. Visual and verbal feedback with breathing techniques were provided. All treatments were on an outpatient basis.

Questionnaires

Constipation Severity Instrument[9]

Constipation Severity Instrument (CSI) includes 16 items of self-report measurements that evaluate constipation symptoms, aids for defecation, frequency of stool passage, consistency, and easy evacuation of stools. Three subscales include obstructive defecation (OD) (six items), colonic inertia (six items), and pain (four items). The possible range of scores is 0–29 on the subscale of the colonic inertia, 0–28 on the subscale of OD, and 0–16 on the subscale of pain.[15] The total score of CSI ranges from 0 to 73 by a composite score for the three subscales.[16] More severe symptoms are represented by higher scores, which are validated with good psychometric properties.[13] Six of the 25 participants did not fully complete the baseline CSI questionnaire, and another two and seven patients did not return the CSI questionnaire after biofeedback and at 6-month follow-up, respectively. These patients were excluded when the comparison analysis of CSI was made.

Constipation-Related Quality of Life[14]

CRQOL questionnaire contains 18 items. Four specific areas to assess the QOL are grouped as follows:[14] (1) social impairment (5 items), (2) distress (6 items), (3) eating habits (3 items), and (4) bathroom attitudes (4 items). A 5-point Likert scale is scored in all items.[14] The subscale is 5–25 for social impairment, 3–15 for eating habits, 6–30 for distress, and 4–20 for bathroom attitudes.[14] A total score ranged from 18 to 90, and a poorer QOL is represented by a higher score of CRQOL.[14] Seven of the 25 participants did not fully complete the baseline CRQOL questionnaire, and another one and eight patients did not return their CRQOL questionnaire after biofeedback and at 6-month follow-up, respectively. They were excluded when the comparison analysis of CRQOL was made.

Because a summative method was used to calculate the CSI and CRQOL scores, we excluded the data points from the analysis if one or more responses were missing in order to prevent an artificial deflation of the total score.[10]

Patient global satisfaction survey

This is a short internal survey about patients' experience with biofeedback therapy in the University of California, San Francisco (UCSF), which includes questions of how the patient feels about the biofeedback treatment and the level of improvement in patient's symptoms and QOL.

Statistical analysis

Descriptive numerical parameters were presented using mean ± standard deviation or medians with interquartile range for nonnormally distributed variables. Nonparametric tests were performed to compare the parameters of CSI, CSI subscales, CRQOL, and CRQOL subscales.[4] The biofeedback therapy effect on symptoms and life quality was assessed by determining the measurement differences before and after therapy, as well as before and at 6-month follow-up using the Wilcoxon signed-rank test. P < 0.05 was recognized as statistical significance. The SPSS software (version 23.0 for Windows, SPSS Inc., Chicago, IL, USA) was used for statistical analyses.


  Results Top


A total of 25 patients were enrolled in the study, including 20 women (80%) and 5 men (20%). The mean age was 58.6 ± 15.0 years (range: 19–83 years). Demographic data for participants at baseline are summarized in [Table 1]. Nearly half of these patients had a history of abdominal surgery. About one-third of the patients reported a history of irritable bowel syndrome. A history of psychiatric condition including anxiety and depression was found in 11 patients. Chronic pain was also noted in seven patients. Eighteen patients had symptoms of constipation for more than 1 year. Before treatment, ten patients had prolonged evacuation for more than 10 minutes. About two-third of these patients (n = 19) had one or more bowel movements per day, and six patients had two or fewer bowel movements per week. Seven patients could not express their stool consistency due to laxative use and another four patients had hard and lumpy stool. Abdominal pain and abdominal bloating were the complaints in 12 and 11 patients, respectively. Five patients needed enemas monthly or less, and a finger in anus was needed in five patients to help have a bowel movement.
Table 1: Demographic data of patients

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During anorectal examination, eight patients had increased resting anal tone and 13 patients had paradoxical movement of puborectalis muscle. Rectocele was found in 12 patients. [Table 2] summarizes the results of anorectal physical examinations and physiology tests at baseline. The mean anal resting pressure and squeezing pressure were within normal limits in these patients. No specific abnormality was found in the value of the median rectal sensation volume and median rectal maximal volume. Among twenty patients who returned the global satisfactory survey after biofeedback, 15 (75%) patients reported a satisfactory response (improvement >50%) of constipation symptoms and QOL.
Table 2: Anorectal physical examination and physiology test result

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After biofeedback therapy, the number of patients who strained for defecation was reduced (10 vs. 5 vs. 4). CSI total score decreased by 11.4% immediately after biofeedback (35.0 vs. 31.0, P = 0.06) and had a statistically significant decrease at 6 months after therapy [35.0 vs. 30.0, P = 0.05, [Table 3] and [Figure 1]. Among the three subscales of CSI, only the CSI OD subscale had a significantly decreased score both immediately after biofeedback (21.0 vs. 16.5, P < 0.01) and at 6 months after therapy (21.0 vs. 18.5, P = 0.03). Drops of 21.4% and 14.3% on CSI OD subscale were noted, respectively, immediately after biofeedback and 6 months after biofeedback. Even after finishing the therapy, the trend of decreasing CSI OD subscale persisted in some patients up to 6 months after therapy [Figure 2]. The subscales of colonic inertia and pain did not have statistically significant differences immediately after biofeedback or at 6 months after biofeedback.
Table 3: The Constipation severity instrument before biofeedback therapy, immediately after 6 sessions of biofeedback therapy, and at 6 months following biofeedback therapy

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Figure 1: Changes of the Constipation Severity Index total score at baseline, immediately after biofeedback therapy, and at 6 months after biofeedback therapy

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Figure 2: Changes of the subscale on obstructive defecation of Constipation Severity Index at baseline, immediately after biofeedback therapy, and at 6 months after biofeedback therapy

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Although the mean CRQOL total score decreased immediately after biofeedback (53.5 vs. 50.0) and at 6 months after therapy (53.5 vs. 49.0), both did not reach statistical significance [Table 4] and [Supplementary Figure 1]. We found that biofeedback therapy may reduce the level of distress and then improve the life quality even after only six sessions of therapy. Among the four subscales of CRQOL, only the distress subscale decreased significantly immediately after biofeedback [24.0 vs. 18.0, P = 0.02, [Figure 3]. A decrease of 25.0% from previous CRQOL distress subscale was noted. The subscales on eating habits, bathroom attitudes, and social impairment did not change significantly immediately after biofeedback or at 6 months after biofeedback.
Table 4: Constipation-Related Quality of Life Instrument scores before biofeedback therapy, immediately after 6 sessions of biofeedback therapy, and at 6 months following biofeedback therapy

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Figure 3: Changes of the subscale on depression of Constipation-Related Quality of Life at baseline, immediately after biofeedback therapy, and at 6 months after biofeedback therapy

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  Discussion Top


The CSI and CRQOL have seldom been used as tools of efficacy to assess treatments for constipated patients since their validation. Till date, only one study had evaluated the effect of biofeedback by using CSI.[9] Unfortunately, no statistical comparison could be made due to a small sample size in that study. This is the first study to demonstrate the effect of biofeedback therapy using CSI and CRQOL scores. Although our study sample is likely underpowered for statistical significance, we do find clinically important differences after analysis. Our study showed that the only significantly improved constipation-related symptom after biofeedback was the OD symptom, which was clearly demonstrated by a 21.4% drop of CSI OD subscale immediately after biofeedback and a 14.3% drop of CSI OD subscale 6 months after biofeedback. We also performed repeated measures analysis, and the significance of biofeedback on CSI OD subscale was the same (ANOVA, P < 0.01). This was not surprising as biofeedback has traditionally been used to specifically address pelvic floor dyssynergia. The CSI total score also decreased after treatment and at 6-month follow-up and reached a borderline significant difference. Furthermore, we found that biofeedback therapy decreased the level of distress and improved the QOL even after only six sessions of therapy. Both CSI and CRQOL are useful tools to evaluate the response of constipated patients after biofeedback therapy.

Because few reports have studied the success of biofeedback by investigating its effect on CRQOL, there is still no consensus regarding which questionnaire is a better surrogate. Heymen et al. used the SF-36 and the Patient Assessment of Constipation QOL Questionnaire (PAC-QOL) in a randomized trial and evaluated the impact on QOL after biofeedback.[8] Although at 3-month follow-up, the biofeedback group had a trend of higher summary scores on the SF-36 and lower summary scores on the PAC-QOL, both differences were not statistically significant. The present study is the first study to evaluate the impact on QOL after biofeedback by using CRQOL. Although we did observe a decreased CRQOL total score after biofeedback, which represented a better QOL, the difference was not statistically significant and was primarily related to the distress subscale change. Further investigation with a larger sample size is required to fully assess this measure.

The reported satisfactory response of 75% after biofeedback in our study was similar to those of several other studies in the literature.[6],[8],[17],[18] Several randomized trials have revealed that biofeedback therapy for pelvic floor dyssynergia is better than placebo, muscle relaxant, or standard therapy with diet, exercise, and laxatives.[8],[19],[20],[21] The long-term effect of biofeedback was sustained up to 1 year or even more than 2 years in selected studies.[20],[21],[22],[23] However, the effect on QOL was seldom mentioned.[4],[24] Although we did not observe a significant change in CRQOL total score after biofeedback, the subscale of distress did improve. Psychosocial factors have been assumed to lead to the success of biofeedback.[9] A good relationship with the biofeedback therapist is suggested to be an important factor of completing the treatment course and reaching a higher success rate.[25],[26] This indicates that the response to treatment is not simply a physiological one but incorporates a complex mechanism involving a patient's psychological state.

Our study is unique because we demonstrated the effects of biofeedback therapy at three time points: before, immediately after, and 6 months after treatment, which provided a serial change of constipated-related symptoms and QOL in individual patients. Even after finishing the therapy, the trend of decreasing scores on the OD subscale persisted in some patients up to 6 months after the therapy. We also noticed that some patients had a rebound of OD subscores after 6 months of therapy. A previous study showed that 17% of initial responders to biofeedback therapy reported a worse status when queried more than 6 months after the end of biofeedback.[22] The probability of maintaining an effect of biofeedback was 65% at 1 year, 60% at 2 years, and 58% at 5 years later.[22] Thus, it may be necessary to recommend periodical follow-up after biofeedback and suggest these patients to return for one or two “tune-up” sessions at that time when their symptoms of constipation recur.

The primary limitation of our study is the small sample size due to difficulty in obtaining complete information in the enrolled patients. This limited our ability to assess statistically significant difference in outcome and to evaluate the impact of other variables, such as medical history, on the outcomes. Furthermore, our analysis was solely using subjective parameters such as questionnaires to evaluate the improvement of symptoms, rather than objective measurements from anorectal manometry evaluations. Several studies have reported the lack of correlation between improvement of symptoms and changes in anorectal manometry;[18],[23],[25],[27] however, an objective surrogate of successful treatment needs to be validated in the future. At UCSF, we use a protocol which consists of dietary recommendations, achieving an optimal regimen of laxatives, and pelvic exercise in addition to the biofeedback therapy. Thus, we cannot differentiate the effects of biofeedback from the effects of adjuvant treatment. A well-controlled randomized trial would be useful to determine the differences of efficacy in these treatment modalities.


  Conclusions Top


Biofeedback is an effective treatment for constipated patients, which in our study, mostly improves the symptoms of OD. It is a valuable routine management and easily tolerated therapy with no long-term side effects.[6] The effects of biofeedback were mainly on improving OD symptoms in constipated patients and decreasing the scores of distress subscale of the constipation-specific QOL. CSI and CRQOL are both useful tools to evaluate the response of constipated patients after biofeedback therapy. For patients who have chronic constipation and do not have symptomatic improvement after basic interventions of diet and laxatives, referral to a specialized center for complete anorectal physiological examinations and biofeedback therapies is recommended.[4]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
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    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

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