FIBRE-PD

Overview

Initiative type

Framework

Status

Deliver

Published

28 August 2019

Summary

FIBRE-PD is a randomised controlled trial assessing the feasibility, adherence, and efficacy of psyllium husk in improving gut motility and reducing constipation in peritoneal dialysis patients.

Key dates

October 2022 - October 2023

Partnerships

Aim

FIBRE-PD is a parallel-arm open-label randomised controlled study which aims to explore recruitment, adherence, efficacy and safety of implementing psyllium husk to patients receiving Peritoneal dialysis (PD) compared to standard care.

Outcomes

  • Feasibility: 67% recruitment rate of eligible patients (target of 70% achieved)
  • Adherence:  High adherence rate (78%) in the intervention group (psyllium husk)
  • Retention: High retention rate (77%) in the intervention group
  • Clinical Outcomes: Observed improvement in gastrointestinal symptoms and symptom burden in the intervention group compared
    to the control group (Movicol®.
  • Patient Reported Outcomes: Improved quality of life reported by patients in the intervention group
  • Safety: No adverse outcomes reported

Background

Peritoneal dialysis (PD) is a widely used home dialysis modality in Australia, with approximately 17% of dialysis patients on this therapy. One of the most common and problematic side effects experienced by patients receiving PD is constipation. This issue arises from a combination of factors, including strict fluid restrictions, low dietary fibre intake, multiple comorbidities such as diabetes, and the use of medications like phosphate binders, diuretics, and iron supplements.

The prevalence of constipation in PD patients leads to significant complications, including mechanical and infectious issues such as drainage obstruction, poor fluid removal, catheter migration, and peritonitis. A study by Su et al. (2012) found that constipation was directly linked to a higher incidence of peritonitis, making it a serious health concern for this patient population. In addition to physical complications, constipation severely affects the quality of life for PD patients. The discomfort, bloating, and reduced bowel movements may lead to emotional distress, further impacting their well-being.

The global Standardised Outcomes in Nephrology (SONG) initiative has also highlighted gastrointestinal issues, including constipation, as key outcomes that matter to PD patients, indicating the importance of addressing these symptoms for improving overall care. Current treatments for constipation in PD patients largely consist of laxatives, with Movicol® (macrogol-3350 + sodium chloride + bicarbonate + potassium chloride) being the most commonly used. While Movicol® is generally effective, its use is often associated with poor tolerance, leading to non-adherence. Patients are required to take up to eight sachets per day, costing approximately $4.72 daily, which contributes to both financial and pill burden. Despite its efficacy, many patients continue to experience symptoms of constipation, or other gastrointestinal related side effects such as bloating, frequent loose stools, abdominal cramps or nausea, suggesting that alternative treatment options are needed. Psyllium husk, a natural soluble fibre supplement, has been identified as a potential alternative to traditional laxatives. Psyllium works by increasing stool size and stimulating bowel activity, making it easier to pass stools. It is also a more cost-effective option, with a daily dose of 8g costing only $0.41.

Previous studies in general populations have demonstrated that psyllium is more effective than insoluble fibre in improving bowel function, increasing stool output, and relieving constipation. Additionally, psyllium has shown benefits in other areas such as improving glycaemic control and lipid profiles in patients with type 2 diabetes. Despite the promising evidence in non-dialysis populations, there is limited research on the safety, tolerability, and efficacy of psyllium husk in PD patients. Given the high burden of constipation in this group and the potential advantages of psyllium, the FIBRE-PD trial aims to investigate whether psyllium husk supplementation can improve gut motility, reduce constipation, and enhance the quality of life in PD patients.

Methods

FIBRE-PD is a prospective, parallel-arm, open-label feasibility trial conducted at the  Peritoneal Dialysis Unit of the Princess Alexandra Hospital, Brisbane, Australia, from October 2022 to October 2023. Participants were randomly assigned in a 1:1 ratio to receive either psyllium husk (intervention group) or continue their routine Movicol®  treatment (control group) for a 28-day period. The primary outcome was to assess the feasibility of recruiting 60 patients, representing 70% of the potentially eligible PD patients. Secondary outcomes included adherence, retention, safety, and patient-reported  outcomes, including gastrointestinal symptom burden and quality of life.

Eligible participants were adults (≥18 years) on PD for at least three months who were currently using Movicol® to manage constipation. Patients were excluded if they had a history of significant  bowel surgery (e.g., radiation therapy or large bowel resection), active inflammatory bowel disease, or other conditions that could interfere with study participation. Written informed consent was obtained from all participants. Ethical approval for the study  was granted by the Metro South Human Research Ethics Committee (HREC/2021/QMS/76238). Upon meeting inclusion criteria, participants were randomly assigned using a centralized, concealed randomisation method (1:1 ratio) to either the intervention group (psyllium  husk) or the control group (Movicol®).

The study adopted a flexible, patient-centred approach to treatment, allowing participants to adjust their dose based on their symptoms. The intervention group received a 1kg bag of psyllium husk and a 20ml measuring  scoop. The initial dose was 8g per day (1 scoop), with the option to increase the dose if needed, based on bowel movement frequency and stool consistency. Participants in the intervention group were instructed to cease their regular use of Movicol® during  the study period. The control group continued their usual Movicol® regimen throughout the study. Data were collected at baseline (day 0) and at weekly intervals for 28 days. Both groups were provided with a daily checklist to record their product usage. Primary  outcomes focused on feasibility (recruitment of 60 patients, representing 70% of eligible PD patients). Secondary outcomes included adherence (measured by product usage), retention (measured by participant completion of the study), safety (via serum potassium  monitoring), and patient-reported outcomes such as gastrointestinal symptom burden and quality of life (measured using standard validated tools).

To ensure participant adherence and protocol fidelity, both groups received weekly reminders and support from  research staff. Participants were encouraged to report any adverse events or concerns throughout the study. Adherence was tracked through daily checklists, and participants were given the flexibility to adjust their doses according to bowel motion frequency and stool consistency (assessed via the Bristol stool score). Serum potassium levels were monitored at day 14 to assess safety, particularly to detect any electrolyte imbalances associated with psyllium husk use.

The study implemented a patient-centric, flexible  approach to treatment in order to enhance feasibility and adherence. By allowing dose adjustments based on individual symptoms, we aimed to optimise outcomes while maintaining participant safety. Regular communication and follow-up with participants helped  ensure high retention and adherence throughout the study period.

Discussion

The FIBRE-PD study aimed to evaluate the feasibility of using psyllium husk to manage constipation in patients receiving peritoneal dialysis (PD). Although the study did not meet its recruitment target, it successfully enrolled over two-thirds of eligible participants and demonstrated that psyllium husk was as effective and safe as Movicol® for managing constipation. Notably, the intervention group showed high adherence and retention, and reported considerable improvements in gastrointestinal symptoms, particularly in stool consistency and quality of life.

The success of the FIBRE-PD study was closely linked to a patient-centred approach, which offered flexibility in dosing and allowed for close monitoring of adherence and symptom relief. This approach was critical in maintaining high retention and adherence rates, particularly in a population with complex health needs. The study’s single-centre design and the dedicated involvement of research staff were also essential to ensure the smooth running of the trial and accurate data collection.

One of the main lessons learned was the unexpectedly high number of ineligible patients due to non-adherence to prescribed Movicol®, a factor that significantly impacted recruitment. Prior studies have shown that Movicol® is often poorly tolerated due to side effects like bloating and cramping, which may contribute to non-adherence.


Although the reasons for non-adherence were not specifically explored in this study, this highlights a critical gap in current PD care, where existing bowel management strategies fail to meet patient needs. The study’s limitations include its small sample size and single-centre design, which restricts the generalisability of the findings. Additionally, the open-label design introduces potential bias, especially in patient-reported outcomes. Another limitation was the failure to capture data on hard clinical endpoints, such as catheter failure, which are of paramount importance in PD.

Strengths: FIBRE-PD demonstrated the feasibility of using psyllium husk in a real-world clinical setting, with high patient adherence and a positive impact on gastrointestinal symptoms and quality of life. The study design was robust, employing randomisation, safety monitoring, and adherence tracking, which ensured the reliability of the results. Weaknesses: The high ineligibility rate due to non-adherence with Movicol® and the small sample size are significant limitations. The lack of clinical endpoint data also limits the ability to draw definitive conclusions about the impact of psyllium husk on long-term PD outcomes. Opportunities: There is a clear opportunity to expand this study into larger, multi-centre trials that would include a more diverse patient population and allow for the assessment of clinical outcomes, such as catheter failure and hospitalization rates.

Additionally, this study opens the door to investigating other fibre supplements as potential alternatives to current laxatives used in PD care. In terms of broader implementation, this project has the potential to succeed beyond the study’s initial scope. It could be expanded to other Queensland Health hospitals and even other dialysis centres across Australia. Given the promising results in this study, the next steps should include larger, multi-centre trials to confirm these findings and evaluate their impact on mechanical complications and long-term clinical outcomes in PD patients.

References

1. ANZDATA 43rd Annual Report 2020 (Data to 2019) – anzdata.org.au

2. Kosmadakis G,  Albaret J, Da Costa Correia E, Somda F, Aguilera D. Constipation in Peritoneal Dialysis Patients. Peritoneal dialysis international: journal of the International Society for Peritoneal Dialysis. 2019;39

3. Su, Chun-Yan & Pei, Juan & Lu, Xin-Hong & Tang, Wen.  (2012). Gastrointestinal symptoms predict peritonitis rates in CAPD patients. Clinical nephrology. 77. 267-74. 10.5414/CN107249.

4. Sumida K, Yamagata K, Kovesdy CP. Constipation in CKD. Kidney International Reports. 2020;5(2):121-134. doi:10.1016/j.ekir.2019.11.002

5. Manera, Karine E., David W. Johnson, Jonathan C. Craig, Jenny I. Shen, Lorena Ruiz, Angela Yee-Moon Wang, Terence Yip et al. "Patient and caregiver priorities for outcomes in peritoneal dialysis: multinational nominal group technique study." Clinical Journal  of the American Society of Nephrology 14, no. 1 (2019): 74-83.

6. Sutton D, Dumbleton S, Allaway C. Can increased dietary fibre reduce laxative requirement in peritoneal dialysis patients? J Ren Care. 2007 Oct-Dec;33(4):174-8. doi: 10.1111/j.1755-6686.2007.tb00068.x.  PMID: 18298035.

7. Sutton D, Ovington S, Engel B. A multi-centre, randomised trial to assess whether increased dietary fibre intake (using a fibre supplement or high-fibre foods) produces healthy bowel performance and reduces laxative requirement in free living  patients on peritoneal dialysis. J Ren Care. 2014 Sep;40(3):157-63. doi: 10.1111/jorc.12056. Epub 2014 Mar 20. PMID: 24650128.

8. McRorie JW Jr, Fahey GC Jr, Gibb RD, Chey WD. Laxative effects of wheat bran and psyllium: Resolving enduring misconceptions about  fiber in treatment guidelines for chronic idiopathic constipation. J Am Assoc Nurse Pract. 2020 Jan;32(1):15-23. doi:10.1097/JXX.0000000000000346. PMID: 31764399.

9. Noureddin S, Mohsen J, Payman A. Effects of psyllium vs. placebo on constipation, weight,  glycemia, and lipids: A randomized trial in patients with type 2 diabetes and chronic constipation. Complement Ther Med. 2018 Oct;40:1-7. doi: 10.1016/j.ctim.2018.07.004. Epub 2018 Jul 10. PMID: 30219432.

Key contact

Chloe Howard

Clinical Nurse

Metro South Hospital and Health Service

Email:  chloe.howard@health.qld.gov.au

Last updated: June 2025

Back to top