Biofeedback Therapy in Children with Functional Constipation in Tehran, Iran


Azizollah Yousefi ORCID 1 , Faezeh Fazelnia 2 , Farnaz Yousefi 2 , Ania Riahi 3 , * , Elahe Norouzi ORCID 4

1 Pediatric Growth and Development Research Center, Institute of Endocrinology and Metabolism Iran University of Medical Sciences, Tehran, Iran

2 Iran University of Medical Sciences, Tehran, Iran

3 Pediatrician, Pediatrics Department, Rasul _e_ Akram Medical Complex Hospital, Iran University of Medical Sciences, Tehran, Iran

4 Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran

How to Cite: Yousefi A, Fazelnia F, Yousefi F, Riahi A, Norouzi E. Biofeedback Therapy in Children with Functional Constipation in Tehran, Iran. Iran J Pediatr.31(4):e111221. doi: 10.5812/ijp.111221.


Iranian Journal of Pediatrics: 31 (4); e111221
Published Online: June 23, 2021
Article Type: Research Article
Received: December 1, 2020
Revised: April 10, 2021
Accepted: April 27, 2021


Background: Functional constipation is a common disorder in pediatrics and affects about 30 percent of children, causing several physical and emotional complications and having a considerable impact on health expenses and quality of life. Biofeedback is a behavioral therapy that gives the patient information about the activity of pelvic floor muscles and teaches the patients how to properly contract and relax the sphincter. Biofeedback therapy is the most effective in those with constipation due to pelvic floor dyssynergia, which is the abnormal function of sphincter muscles and affects 40% of children with constipation.

Objectives: This study aimed to evaluate the effect of biofeedback therapy in children with chronic functional constipation unresponsive to medical and conventional treatments.

Methods: Forty-four children with functional constipation (according to ROME 4 criteria) unresponsive to at least six months of taking medical treatment and pelvic floor dyssynergia according to anorectal manometry were selected for biofeedback therapy. After six months, symptoms of patients and the need for laxative consumption were compared to those before therapy.

Results: Considering ROME 4 criteria, clinical improvement was achieved in 59.1% of patients. Comparison of symptoms shows improvement in 52 - 89 % of cases.

Conclusions: In pediatric patients with functional constipation and pelvic floor dyssynergia who do not respond to conventional treatments, biofeedback therapy could be an alternative therapy, and its effects last for at least six months.

1. Background

Given that normal defecation is a sign of relative gastrointestinal health, any case of abnormal defecation needs further examination. Constipation is among the common conditions that make patients visit a doctor (1-3). Constipation may be caused by either extra-gastrointestinal factors (e.g., endocrine, neurological, and metabolic diseases; electrolytic, rheumatologic, and psychological disorders; and side effects of drugs) or intra-gastrointestinal factors such as anatomical disorders (4, 5). Constipation is a common complaint in children, with a prevalence of up to 29.6% (6). About 95% of constipation cases in children are of the functional type with no organic finding (7). The children that complained of constipation account for 3 - 5% of visits to pediatricians and 11 - 25% of visits to pediatric gastroenterologists (1, 8-11). Pathophysiology of functional constipation occurs as a vicious cycle of the progressive accumulation of stool with hard consistency. This accumulation takes place after a painful experience of difficult defecation, and the child learns to prevent defecation by contracting the pelvic floor muscles due to fear of pain (2). Since constipation is a chronic disorder, it can cause behavioral and cognitive complications, academic failure, psychological stresses for children and their families, and finally, reduces the quality of life (12, 13). Common treatments of constipation are behavioral therapies and prescribing laxatives and enema (14, 15). There are several treatments for constipation that fall into two categories: non-pharmacological treatments and pharmacological treatments (16). Pelvic floor dyssynergia is usually diagnosed by anorectal manometry. This technique involves the measurement of recto-anal inhibitory reflex (RAIR), cough test, squeeze test, push test, and resting pressure. RAIR is the normal reflexive response to rectal distension. Biofeedback therapy is based on encouraging and teaching appropriate behaviors along with providing audiovisual cues to children so that they learn how to contract and relax the perineal muscles to achieve the best result in defecation (17, 18). Given that biofeedback therapy can be effective in treating chronic constipation in children, further studies are needed to definitively confirm the effectiveness of this treatment.

2. Methods

This was a prospective interventional case series. The statistical population consisted of all patients with functional constipation aged 5 - 18 years who visited Rasool Akram Pediatric Gastroenterology Clinic and Ali Asghar Hospital in 2017 - 2018. ROME 4 was employed to diagnose functional constipation. The criteria were as follows: (1) defecations of 2 or fewer per week; (2) painful bowel movements; (3) bowel movements of large volumes; (4) defecation refusal; (5) dirty underwear at least once a week in children who can defecate voluntarily; and (6) the existence of fecal masses in the rectum. Those who had at least two of the above-mentioned conditions or complained of these conditions at least once a week were diagnosed with functional constipation. The participants were under treatment with Pidrolax; polyethylene glycol (PEG) powder manufactured by Sepidaj company; in a dose of one heaping tablespoon in a cup of water once a day for at least six months. They were also recommended to have a high-fiber diet and try to defecate at certain times of the day, especially after meals. The participants who did not respond to this treatment were asked to undergo conventional anorectal manometry by an MMS manometer (Medical Measurement System manufactured in the Netherlands) to examine any possible dysfunction in pelvic floor muscles. In the case of pelvic floor dyssynergia (RAIR along with the abnormal result of any of the cough test, squeeze test, and push test or high resting pressure), the participants were recommended to visit a physiotherapy clinic to undergo pelvic floor physiotherapy by electromyography-based biofeedback. Biofeedback was performed by means of MMS equipment (manufactured in Netherland) in ten sessions of 30 minutes therapy twice a week by a well-trained physiotherapist for each patient. The participants who did not complete the treatment or participated in fewer sessions, or had any signs or symptoms of anxiety disorders in their first visits were excluded from the study. The participants were allowed to take laxatives during the trial, depending on their health status.

The data were collected by filling out a questionnaire in in-person or telephone interviews with parents of children before the trial and 6 months after the last biofeedback session. We used the IBM SPSS Statistics 26 to perform statistical analyses. Two-way repeated measures analysis of variance (ANOVA) was used to compare the group effect. If subjects were lost to follow up, an intention-to-treat analysis was conducted. Student t-test was used to compare the within-group changes when ANOVA revealed a significant difference. Statistical significance was determined by a two-sided P-value of less than 0.05. In addition, if any demographic or clinical characteristics were significantly imbalanced, analysis of covariance was performed to adjust the imbalance.

The research was approved primarily by the Ethics Committee of Iran University of Medical Sciences with the code number of IR.IUMS.FMD.REC 1396.09352527436 and was conducted in accordance with the Helsinki Declaration.

3. Results

The results showed that 30 participants were male and 14 participants were female. The participants aged between 5 and 14 years, with a mean of 8.02. Demographic data, weight status, and manometry results of patients are summarized in Table 1. Twenty-six participants did not complain about clinical symptoms after the trial, indicating an improvement rate of 59.1%. Moreover, 25 participants (56.8%) discontinued laxatives after biofeedback therapy.

Table 1. Baseline Characteristics and Manometry Results in Children with Functional Constipation Underwent Biofeedback Therapy (n = 44)
ParametersNo. (%)
Age group
< 8y20 (45.4)
≥ 8y24 (54.5)
Male30 (31.8)
Female14 (68.1)
Underweight3 (6.8)
Normal33 (75.0)
Overweight5 (11.4)
Obese3 (6.8)
Manometry results
Abnormal cough test6 (13.6)
Abnormal squeeze test8 (18.2)
Abnormal push test41 (93.2)
High resting pressure9 (29.5)

The results related to the pretest and posttest comparison of constipation symptoms showed that 34 participants (77%) had reported twice or fewer bowel movements per week before the study, whereas 18 of them (52%) reported three times or more bowel movements per week after the study. Since the McNemar test revealed that the significance level was 0.0001, it can be concluded that there was a significant difference between the pretest and posttest results of bowel movement frequency. The results indicated that 41 participants (93%) complained of painful or hard bowel movements before the study, but 27 of them (65%) were improved after the study. Since the McNemar test revealed that the significance level was 0.0001, it can be concluded that there was a significant difference between the pretest and posttest results of painful or hard bowel movements. Nine participants (20%) had reported anal stimulation for defecation before the study, whereas eight of them (89%) did not need to use this method for defecation after the study (P-value of 0.0001). The results demonstrated that 32 participants (72%) complained of incomplete bowel movements before the study, whereas 23 of them (72%) were improved after the study (P-value of 0.0001), which can be considered a significant difference between the pretest and posttest results of incomplete bowel movements. The results also showed that 32 participants (72%) complained of dirty underwear at least once a week before the study, but 22 of them (68%) did not have such a problem after the study (P-value of 0.0001), so it can be concluded that there was a significant difference between the pretest and posttest results in this regard. The results indicated that 35 participants (79%) used to refuse defecation before the study, whereas 23 of them (65%) improved after the study. The McNemar test revealed that the significance level was 0.0001, which means a significant difference between the pretest and posttest results. The results also revealed that 32 participants (72%) did not complain of large-volume bowel movements before the study, whereas 18 of them (56%) improved after the study. Since the McNemar test revealed that the significance level was 0.0001, it can be concluded that there was a significant difference between the pretest and posttest results. It can be stated that all studied symptoms were improved in more than 50% of cases after the trial, as there was a significant difference between pretest and posttest results (Figure 1).

Figure 1. Frequency of symptoms pre- and post-biofeedback therapy in patients with functional onstipation. Abbreviation: BF, biofeedback therapy.

The data showed that 20 participants aged under 8 years and 24 participants aged 8 years or more. The results revealed that 12 participants from the first age group (60%) and 14 participants from the second age group (58.3%) responded to treatments. The chi-square test showed that the p-value was equal to 0.9, which means that there was no significant difference between the two age groups in terms of treatment response based on the ROME 4 criteria. The participants of this study included 30 boys and 14 girls. The results indicated that 50% of girls and 65% of boys successfully responded to treatments. Since the P-value was obtained 0.402 in the chi-square test, it can be concluded that there was no significant difference between girls and boys in response to biofeedback.

4. Discussion

This study aimed to investigate the therapeutic effects of biofeedback on children who complained of chronic constipation resistant to conventional treatments. These findings are presented to the patient in the form of video or audio messages obtained from the function of the sphincter during defecation maneuvers to train the patient in how to properly contract or relax the sphincter muscles and enhance rectal sensory perception (19, 20). Several techniques have been introduced to perform biofeedback, the most common of which are manometry-based biofeedback and electromyography-based biofeedback. The first method measures sphincter pressure in the rectum by a sensor, whereas the second method measures the electrical activity of muscles by electrodes placed in the rectum or on the surface of the perineum (21, 22). Although the high efficacy of both methods has been reported in many studies (23), electromyography-based biofeedback was employed in this study.

Although numerous studies have proven the therapeutic effects of biofeedback in children (24-26) and adults (19, 21, 23, 27-31), the findings of some studies have shown that there is no significant difference between the therapeutic results of biofeedback and other conventional treatments (15, 32-34). The results of a review study in 2014 demonstrated that there was insufficient evidence to evaluate the therapeutic effects of biofeedback in patients with functional constipation, considering the poor methodology of the previous studies (35). In a similar study conducted by Jarzebicka et al., the therapeutic effects of biofeedback on 44 children with constipation and pelvic floor dyssynergia have been proven (36). However, a major limitation of their study was its retrospective methodology based on the medical records of patients. The present study was performed based on a similar method but in an interventional and prospective manner.

Among the similar studies, the greatest sample size was related to the studies conducted by Van der Plas (17) (n = 192), Engelenburg-van Lonkhuyzen (24) (n = 53), Olness (n = 50), and Jarzebicka (36) (n = 44). Previous studies have shown that the therapeutic effects of biofeedback depend on the correct choice of the patient. An important factor in the selection of patients with functional constipation was the underlying cause of the disease. Two major causes of functional constipation mentioned in this study were slow-transit constipation and pelvic floor dyssynergia (35, 37). Previous studies have shown that biofeedback therapy can be more effective in patients with functional constipation caused by pelvic floor dyssynergia (25, 29, 30, 38, 39). This inclusion criterion was not taken into account in some studies that have not proven the therapeutic effects of biofeedback (17, 33, 34, 40). The findings of Van der Plas et al. showed that there was no significant difference between the therapeutic effects of biofeedback and medical treatments; however, their study was conducted on a sufficient number of samples (71 patients). Nolan et al. showed that there was no significant difference between the therapeutic effects of biofeedback and drug therapy; however, their study did not include the etiology of constipation. But the sample size was not statistically sufficient in these two studies. In this study, manometry was performed to measure several factors, including RAIR, cough test, squeeze test, push test, and resting pressure. The result of this test was normal for all participants. The normal result of RAIR, along with abnormal results of one of cough test, squeeze test, and push test or high resting pressure is an indication of pelvic floor dyssynergia (41).

The minimum number of biofeedback sessions has been discussed in some studies. In several randomized clinical trials (RCTs) (22, 27), 4 to 6 sixty-minute sessions were performed twice a week as the initial treatment, and it was recommended to repeat the sessions 1, 3, 6, and 12 months later to achieve more long-lasting therapeutic effects. In another RCT conducted by Engelenburg-van Lonkhuyzen et al. (34), 53 children aged 5 - 16 years with functional constipation underwent biofeedback according to the Dutch protocol. Accordingly, at most 6 sessions of biofeedback were performed over six months. Their findings confirmed the higher effectiveness of biofeedback compared to other conventional treatments. Based on personal experience in the treatment of previous patients, the participants of this study were recommended to attend 10 sessions of biofeedback. Two sessions of 30 minutes were performed twice a week. Some parents refused to complete the recommended number of sessions for reasons such as the child's lack of cooperation, high cost of sessions, or disappointment with the usefulness of the treatment. The follow-up duration is an important factor in evaluating biofeedback outcome. The parents of some children who participated in this study reported that they had observed the improvement of clinical symptoms several weeks after the beginning of biofeedback.

Another factor that can affect the effectiveness of biofeedback is the physiotherapist's experience and skillfulness in performing biofeedback and his/her ability to communicate with children, because biofeedback is a type of training and behavioral therapy for children (12, 32-35, 37-40). For all participants of this study, biofeedback was performed by an individual physiotherapist who was experienced in pediatric pelvic floor physiotherapy.

Based on ROME 4, improvement of symptoms was observed in 59.1 of the participants. Pretest and posttest comparison of symptoms also revealed that all symptoms improved after treatment in more than 50% of cases (an improvement rate of 52 - 89%), which was statistically significant. However, ROME 4 demonstrated that these patients were among those who did not respond to the treatment. It can be hence concluded that ROME 4 alone cannot accurately measure treatment response. The results revealed no significant difference between the two age groups under and over 8 years in treatment response, so it can be stated that age is not a determinant of treatment response in such patients.

Since the symptoms were improved in more than 50% of cases in this study, biofeedback therapy is recommended to be used for the treatment of resistant constipation in children with pelvic floor dyssynergia.

4.1. Conclusion

The study findings suggested that 10 sessions of biofeedback therapy improve symptoms in children with pelvic floor dyssynergia and resistant constipation, and it could be an alternative treatment, which may be added to drug therapy. On the other hand, our findings showed that 56.8% of patients discontinued laxatives after biofeedback therapy.



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