Efficacy of home biofeedback in dyssynergic A prospective pilot study

Authors: Ahmet Omak, Alisina Bulut, Wafi Attaallah

Abstract

Aim

To evaluate the effectiveness of home biofeedback therapy in patients with dyssynergic defaecation.

Method

This single‐centre prospective cohort study was conducted in a tertiary general surgery outpatient clinic. Adult patients with dyssynergic defaecation confirmed according to Rome IV criteria and physiological testing were prospectively enrolled after ethical approval. Participants received training on the use of a home‐based anal biofeedback device and performed biofeedback exercises at home for 30 min daily over a 12‐week period. Changes in Obstructed Defaecation Syndrome Score (ODS‐S) and Patient Assessment of Constipation Quality of Life (PAC‐QoL) score were evaluated.

Results

Twenty‐four patients were included in the study. The median ODS‐S significantly improved from 17.5 (range, 13–20) at baseline to 3 (range, 0–12) after treatment (P < 0.001). The median PAC‐QoL score also showed a significant improvement, decreasing from 104 (range, 65–126) to 49 (range, 32–81) (P < 0.001). Clinical improvement, defined as an ODS‐S < 9, was achieved in 75% of patients.

Conclusion

Home‐based biofeedback therapy is an effective and accessible treatment option for dyssynergic defaecation. Its low cost, ease of use and ability to preserve patient privacy suggest that this modality may serve as a practical first‐line therapy.

What does this paper add to the literature?Although biofeedback is an effective treatment for obstructive defaecation, its use is limited by restricted availability, cost and privacy concerns. This study presents a simple, home‐based anal biofeedback device designed to overcome these barriers and reports its short‐term clinical effectiveness in a prospective pilot cohort.

INTRODUCTION

Dyssynergic defaecation is one of the major causes of functional constipation and is characterized by impaired coordination between the abdominal muscles and the pelvic floor, resulting in paradoxical anal sphincter contraction or inadequate relaxation during defaecation [1]. The estimated prevalence of chronic constipation in the general population is approximately 14%. Among patients with chronic constipation, nearly one‐third have obstructed defaecation, and dyssynergic defaecation is identified in 27%–59% of these cases [2]. Although the exact aetiology remains unclear, dyssynergic defaecation is believed to be a learned behavioural disorder arising from maladaptive toileting habits. Psychiatric disorders, childbirth, anorectal diseases and history of physical or sexual abuse are commonly reported contributing factors [3]. Patients typically present with symptoms such as excessive straining, a sensation of incomplete evacuation, digital manoeuvers, hard stools and pain during defaecation. Diagnosis is established through clinical evaluation, including history and digital rectal examination, supplemented by physiological tests such as anorectal manometry and defaecography. Several symptom scoring systems and quality‐of‐life scales are available to assess disease severity.

Conservative treatments such as dietary modification, exercise and laxatives often provide insufficient relief. More invasive treatments, including anorectal myectomy, partial division of the puborectalis muscle or botulinum toxin injection, may offer short‐term symptom improvement but carry a risk of faecal incontinence. Among available treatment modalities, biofeedback therapy is considered the most effective, with randomized controlled trials reporting success rates of 70–80% [1]. However, access to biofeedback therapy is limited due to the need for specialized equipment, trained personnel, multiple clinic visits and associated financial burden. Consequently, many patients are unable to benefit from this therapy. Therefore, the home‐based biofeedback devices may substantially improve treatment accessibility [4]. This study aimed to assess the effectiveness of home‐based anal biofeedback therapy using a simple device developed in our clinic.

METHOD

Study design and patient selection

This study was designed as a single‐centre, prospective cohort clinical study. Ethical approval was obtained from the Marmara University School of Medicine Clinical Research Ethics Committee (Approval Date: 14 July 2023; no. 09.2023.871). Patients presenting with symptoms of obstructive defaecation were evaluated as part of routine standard clinical care beginning in January 2022. During this period, diagnostic procedures including digital rectal examination, colonoscopy, anorectal manometry and magnetic resonance (MR) defaecography were performed solely based on clinical indications. The prospective research protocol, including systematic data collection, standardized outcome assessment and study‐specific intervention using the home‐based biofeedback device, was initiated only after ethics committee approval. Following ethical approval, eligible patients were prospectively enrolled between July 2023 and September 2024, provided written informed consent and underwent the study‐specific intervention and follow‐up. Patients were eligible for inclusion if they were 18 years of age or older and had a confirmed diagnosis of dyssynergic defaecation according to Rome IV criteria. Patients were excluded if they had cognitive impairment, a stoma, a history of rectal malignancy or inflammatory bowel disease. The study was conducted in accordance with the principles of the Declaration of Helsinki.

Clinical evaluation

All patients underwent a standardized clinical evaluation including digital rectal examination, colonoscopy, anorectal manometry and MR defaecography. The diagnosis of dyssynergic defaecation was established according to the Rome IV criteria based on physiological testing. Dyssynergic defaecation was defined as the presence of paradoxical contraction or inadequate relaxation of the anal sphincter and/or puborectalis muscle during simulated defaecation, accompanied by insufficient propulsive forces, as demonstrated on anorectal manometry. In addition, at least one supportive physiological test was required to confirm the diagnosis, including an abnormal balloon expulsion test or imaging findings consistent with impaired evacuation on MR defaecography.

In addition to physiological assessment, associated anorectal anatomical abnormalities and psychiatric comorbidities were evaluated as part of the clinical work‐up. Anorectal anatomical abnormalities, including rectocele, pelvic floor descent and intrarectal intussusception, were assessed using MR defaecography and recorded by an experienced radiologist. Psychiatric comorbidities were defined based on documented diagnoses of anxiety or depression previously established by the psychiatry department and recorded in the patients' medical records. No independent psychiatric assessment was performed within the scope of this study.

Baseline demographic data, clinical symptoms (including straining, prolonged evacuation, incomplete evacuation, digital manoeuvers, perianal pain, hard stool, bloating, laxative use and urinary incontinence), symptom duration, comorbidities, obstetric history, prior anorectal procedures, anorectal manometry results and defaecography findings were recorded. Symptom severity was assessed using the ODS‐S [5], and quality of life was evaluated using the Patient Assessment of Constipation Quality of Life (PAC‐QoL; Turkish validated version) score [6]. Both were assessed before and after treatment.

Home‐based anal biofeedback training device

The home‐based biofeedback device used in this study allows real‐time visual feedback of anal sphincter pressure changes during contraction and relaxation, enabling patients to observe and correct paradoxical pelvic floor activity.

The developed biofeedback device consists of a sphygmomanometer, an anal biofeedback silicone balloon catheter, and a rotatable visual biofeedback scale, as shown in Figure 1. For infection control and hygiene, each patient was provided with an individual anal balloon catheter for exclusive personal use throughout the study, and the device was not shared between patients at any time.

Home training protocol

Prior to initiation of home‐based training, all patients received a standardized face‐to‐face training session in the outpatient clinic. During this session, the use of the device was explained to the patient in detail, and the patient was asked to perform the technique in our presence.

The device consists of an inflatable balloon connected to a sphygmomanometer that allows real‐time visualization of pressure changes. A manually rotatable coloured scale (red–yellow–green) is placed on the gauge to indicate pressure zones. Before starting the exercise, the patient inflates the balloon and rotates the scale to align the indicator with the zero point. After insertion of the balloon into the anus, resting anal pressure causes a slight increase in the gauge reading. Patients are then instructed to perform squeeze and relaxation manoeuvers while observing the pressure changes on the gauge. The goal of the exercise is to achieve a decrease in pressure towards the zero level during relaxation (Figure 2).

Patients were instructed to perform the exercises for 30 min daily, in a private and comfortable real‐life home environment, for 12 weeks. All patients were evaluated during scheduled face‐to‐face outpatient follow‐up visits throughout the study period. The overall study workflow is illustrated in Figure 3. During the 12‐week study period, no additional concurrent treatments (e.g., new laxatives, dietary interventions, or pelvic floor exercises outside the prescribed protocol) were recommended.

Follow‐up

Patients were evaluated at week 1, week 2 and at months 1, 2 and 3. All device‐based training and evaluations followed the same protocol throughout the study period. During these visits, patients were asked about their clinical improvement and the ODS‐S was recalculated. At the final visit, both the ODS‐S and PAC‐QoL scores were reassessed. Clinical improvement was defined as a post‐treatment ODS‐S < 9.

Outcomes of the study

The primary outcome was to determine the change in ODS‐S and PAC‐QoL scores before and after treatment. The secondary outcome was the prevalence of anorectal anatomical and psychiatric comorbidities accompanying dyssynergic defaecation.

Statistical analysis

Statistical analysis was performed using SPSS version 23.0 (SPSS Inc., Chicago, IL, USA). Sample size calculation indicated that a minimum of 21 patients was required to detect a clinically significant change with an effect size of 0.5, α = 0.05, and power = 80%. Data were expressed as mean ± SD for normally distributed variables or median (interquartile range) for non‐normal variables. Normality was tested using the Kolmogorov–Smirnov test and visual histogram inspection. Paired comparisons were performed using the paired t‐test for variables with normal distribution, whereas the Wilcoxon signed‐rank test was applied for non‐parametric data. A two‐tailed p‐value of < 0.05 was considered statistically significant.

RESULTS

Between January 2022 and September 2024, a total of 91 patients presented with obstructed defaecation symptoms. Of these, 45 patients did not complete the required diagnostic evaluations, 19 patients diagnosed with dyssynergic defaecation did not return for follow‐up, and 3 patients were lost to follow‐up before outcome assessment. Consequently, 24 patients were included in the final analysis (Figure 4).

The median age of the study population was 49.5 years (range, 18–71), and 13 (54.2%) of the patients were female. The mean body mass index was 28.9 ± 5.29 kg/m^2^. A history of prior anorectal surgery was present in 9 (37.5%) patients, and 5 (20.8%) had undergone previous surgical interventions for obstructed defaecation syndrome (ODS). Among these five patients, all surgical procedures had been performed prior to enrolment in the study. Specifically, two patients had previously undergone surgery for intra‐rectal intussusception and one for full‐thickness rectal prolapse, each treated with an open posterior mesh rectopexy (Wells procedure). The remaining two patients had undergone resection rectopexy many years earlier for chronic constipation. Despite these prior operations, their ODS symptoms persisted, and therefore, they were included in the present study. Among female patients, 11 (84.6%) had at least one vaginal delivery, with a median parity of 2 (range, 2–7), and 7 (63.6%) of these had a history of episiotomy. The median duration of symptoms was 60 months (range, 7–300) (Table 1).

Evaluation of presenting symptoms revealed that all patients reported excessive straining, a sensation of incomplete evacuation and a feeling of blockage. Additionally, 95.8% reported bloating, 91.7% had hard stools, 87.5% used digital manoeuvers, 75% experienced perianal pain, 70.8% reported prolonged defaecation (> 30 min), 66.7% had abdominal pain, and 37.5% regularly used laxatives. The median ODS‐S decreased significantly from 17.5 (range, 13–20) at baseline to 3 (range, 0–12) after treatment (p < 0.001). Similarly, PAC‐QoL score improved markedly, decreasing from 104 (range, 65–126) to 49 (range, 32–81) (P < 0.001) (Table 2). Clinical improvement, defined as a post‐treatment ODS‐S < 9, was achieved in 18 (75%) patients.

MR defaecography findings demonstrated that the most common associated structural abnormality was pelvic floor descent in 11 (45.8%) patients. Rectocele and intra‐rectal intussusception were observed in 8 (33.3%) and 6 (25%) patients, respectively (Table 3). A psychiatric disorder diagnosis (obsessive‐compulsive disorder, depression, anxiety, panic disorder) was identified in 18 (75%) patients.

DISCUSSION AND CONCLUSIONS

In this prospective, single‐centre study, the demographic characteristics, clinical features and outcomes of 24 patients with dyssynergic defaecation were evaluated following a 90‐day home‐based biofeedback programme. Both the ODS‐S and PAC‐QoL scores showed significant improvement after treatment, and clinical recovery, defined as a post‐treatment ODS‐S < 9, was achieved in 75% of patients.

Biofeedback remains the most effective treatment option for dyssynergic defaecation [1]. Previous studies comparing office‐based and home‐based biofeedback training have demonstrated that home‐based programmes provide similar therapeutic benefit while reducing treatment burden and cost [7]. For this reason, a home‐based approach was preferred in our study. Despite the widespread use of biofeedback, there is still no universally accepted definition of treatment success. Recent studies in this field vary considerably in terms of patient selection, intervention protocols and outcome assessment methods [8]. In the study by Heymen et al. [9], treatment success was defined based on the patient's subjective report of adequate relief at 3 months, and biofeedback demonstrated a 70% improvement, outperforming both diazepam and placebo. Similarly, Cadeddu et al. [10] evaluated outcomes using the Wexner evacuation score and the Altomare Obstructed Defaecation Score and reported significant reductions in both scores at 6 months in the biofeedback group, whereas no significant change was observed in the control group. In our study, symptom severity was assessed using the ODS‐S, which was validated by Renzi et al. [5] as a simple, reliable and disease‐specific scoring method, with a threshold value of ≥ 9 indicating clinically significant obstructed defaecation. The significant reduction in ODS‐S after treatment, along with a clinical improvement rate of 75% based on achieving a post‐treatment score of < 9, is consistent with previously reported findings in the literature.

Improvement in quality of life is also a key therapeutic goal in dyssynergic defaecation. In the randomized study by Özkütük et al., patients receiving biofeedback demonstrated a significant reduction in PAC‐QoL scores compared with those receiving sham therapy, although the training was delivered in the hospital setting using an anal manometry catheter for visual and verbal feedback [11]. Similarly, Şahin et al. reported a significant improvement in quality of life using the SF‐36 scale in patients treated with manometry‐guided training [12]; however, SF‐36 reflects general health status rather than constipation‐specific impact. In our study, we preferred the PAC‐QoL scale, a validated, reliable and disease‐specific instrument designed to assess quality of life in patients with chronic constipation [6, 13]. Consistent with the findings of Cadeddu et al. [10], we observed a significant improvement in PAC‐QoL scores following biofeedback therapy.

Dyssynergic defaecation may coexist with various structural and functional abnormalities. In the study by Lau et al., biofeedback treatment was beneficial in more than half of the patients, and treatment response was primarily associated with patient compliance rather than the presence of anatomical findings such as pelvic floor descent, rectocele or intussusception [14]. Previous work using the ‘iceberg model’ has shown that patients with rectocele or internal prolapse frequently exhibit accompanying psychological and functional disorders, and that anatomical correction alone does not necessarily improve symptoms [15]. Similarly, in our study, most patients benefited from treatment despite coexisting abnormalities on MR defaecography. Psychiatric comorbidities were also present in 75% of patients, suggesting that dyssynergic defaecation has a significant psychosocial component. Therefore, this condition should be approached as both a functional and psychological disorder, and multidisciplinary management, including psychological support when appropriate, may be necessary.

This study has several limitations that should be acknowledged. The sample size was relatively small, long‐term follow‐up data were not available, and a control group was not included. In addition, subgroup analyses according to dyssynergia subtype could not be performed. These factors may limit the generalizability of the observed treatment effect, and the results should therefore be interpreted with caution. In addition, a proportion of initially eligible patients did not complete the full diagnostic work‐up or follow‐up assessments, which may have introduced a degree of selection bias towards patients who completed the treatment protocol. Consequently, the present findings should be considered exploratory and hypothesis‐generating rather than confirmatory. Despite these limitations, the study also has important strengths. It was conducted prospectively, and all patients underwent objective diagnostic evaluation using anorectal manometry and MR defaecography, ensuring accurate patient selection and phenotyping. Moreover, there are only a limited number of studies in the literature evaluating home‐based biofeedback therapy for dyssynergic defaecation. To our knowledge, this is the first study to assess treatment outcomes using this specific, simple home‐based biofeedback device. The system offers several practical advantages, including enhanced privacy during training, reduced cost, improved accessibility and the ability for patients to perform therapy independently at home. These features may facilitate wider adoption of biofeedback therapy and support its potential role as a first‐line, non‐invasive treatment option in selected patients with obstructive defaecation syndrome.

In this study, home‐based biofeedback therapy was found to be effective in the treatment of dyssynergic defaecation. Given its low cost, ease of use without the need for specialized personnel, accessibility and preservation of patient privacy, home‐based biofeedback may represent a practical and preferable first‐line treatment option for patients with dyssynergic defaecation.

PATIENT CONSENT STATEMENT

Written informed consent was obtained from all participants prior to enrolment in the study.

PERMISSION TO REPRODUCE MATERIAL

This manuscript does not include any material reproduced or adapted from other sources.

CLINICAL TRIAL REGISTRATION

This study was not registered in a public clinical trials registry as it was designed as a single‐arm prospective pilot study evaluating feasibility and short‐term outcomes.

AUTHOR CONTRIBUTIONS

Wafi Attaallah: Conceptualization; writing – original draft; methodology; formal analysis; supervision; writing – review and editing; investigation; validation. Alisina Bulut: Writing – original draft; methodology; writing – review and editing; supervision; formal analysis; validation; investigation. Ahmet Omak: Methodology; visualization; project administration; data curation; investigation; writing – original draft; conceptualization; writing – review and editing.

FUNDING INFORMATION

This research received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.

ETHICS STATEMENT

This Ethics approval was obtained from the Marmara University Clinical Research Ethics Committee (Approval Date: 14 July 2023; No: 09.2023.871).