Senna vs. Polyethylene Glycol 3350 for the Treatment of Retentive Encopresis in Children: a Randomized, Double-blinded, Study

The goal of this clinical trial is to learn which treatment is more effective for children with functional constipation (FC) and fecal incontinence (FI), also called retentive encopresis.

Functional constipation is common in children and can cause pain, embarrassment, social stress, and repeated medical visits. One of the hardest symptoms to treat is fecal incontinence. Two common treatments are polyethylene glycol 3350 (PEG), an osmotic laxative, and Senna, a plant-based stimulant laxative. PEG is often used as standard maintenance therapy, while Senna is increasingly used, especially in children with difficult or refractory constipation. However, there is not enough high-quality evidence comparing these two treatments directly in children with fecal incontinence.

The main question this study aims to answer is:

Does Senna reduce the number of fecal incontinence episodes more than PEG after 3 months of treatment? The study will also assess safety, tolerability, abdominal pain or cramping, use of rescue enemas, treatment satisfaction, and treatment compliance.

This is a prospective, randomized, double-blinded clinical trial. Children will be randomly assigned to receive either daily Senna or daily PEG for 3 months. Neither the families nor the treating medical team will know which treatment the child is receiving. Both medications will be prepared as identical-looking white powder in identical packages.

Participants will be children aged 4 to 18 years who have functional constipation according to Rome IV criteria and have fecal incontinence at least 4 times per week. Children with an organic disease that may cause fecal incontinence, such as Hirschsprung disease, spinal cord abnormalities, or anorectal malformations, will not be included.

Before starting the study medication, all participants will complete a 3-day bowel clean-out using high-dose PEG, with Pico-Salax added on the third day. After this clean-out, children will start their assigned daily treatment, either Senna or PEG. The dose will be based on age and may be adjusted by the physician according to stool consistency, stool frequency, cramping, and the child's clinical response. All families will also receive behavioral advice, including regular toilet sitting twice daily, correct toilet position using a footstool, and going to the toilet when the child feels the need.

Participants will:

• Take daily Senna or daily PEG for 3 months
• Visit the clinic at baseline, 1 month, 2 months, and 3 months
• Complete a 7-day stool and fecal incontinence diary before each visit
• Report abdominal pain, cramping, diarrhea, perianal irritation, or any other adverse events
• Return medication containers so compliance can be checked by weighing the remaining medication
• Complete satisfaction and improvement questionnaires at the 3-month visit

Outcome Measurements:

The primary outcome is the mean number of fecal incontinence episodes per week after 3 months of treatment. This will be measured using a prospective 7-day diary completed by the family before the 3-month clinic visit.

The secondary outcomes, assessed at 3 months, include:

• Change in patient-initiated toilet sitting, meaning times when the child independently says they need to defecate
• The proportion of children who reach 0-1 fecal incontinence episodes per week
• The proportion of children with any improvement, defined as at least 1 fewer fecal incontinence episode per week
• Number of rescue enemas used during the 3-month study period
• Frequency and severity of abdominal pain or cramping
• Parent-reported satisfaction with treatment using a 5-point Likert scale
• Family impression of overall improvement using a 5-point Likert scale
• The proportion of children still meeting Rome IV criteria for functional constipation
• Treatment compliance, defined as good compliance if more than 80% of doses were taken

The study plans to enroll 80 children total, with 40 children in the Senna group and 40 children in the PEG group.

Study Overview

• Status: Not yet recruiting
• Conditions: Encopresis With Constipation and Overflow Incontinence
• Intervention / Treatment: Drug: PEG 3350; Dietary supplement: Senna

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Dotan Yogev, MD; Phone Number: +972-50-8668221; Email: dotany@szmc.org.il
• Study Contact Backup: Name: Adi Eindor-Abarbanel, MD; Phone Number: +972-533326633; Email: adiabarbanel@gmail.com

Study Locations

• Israel
  • Be’er Ya‘aqov, Israel
    • Shamir Medical Center
    • Contact: Adi Ein Dor
  • Jerusalem, Israel, 91031
    • Shaare Zedek Medical Center
    • Contact: Zivia Shavit, Msc; Phone Number: +972-54-2520204; Email: zivias@szmc.org.il
    • Principal Investigator: Dotan Yogev, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Children aged 4 to 18 years.
• Diagnosis of functional constipation according to Rome IV criteria.
• Fecal incontinence occurring ≥4 times per week.
• Treatment-naïve or treatment-experienced (i.e., any of the following treatments in the past: PEG, senna, bisacodyl and rectal disimpaction) patients.

Exclusion Criteria:

• Presence of organic disease that causes or contributes to fecal incontinence (e.g., Hirschsprung disease, spinal cord anomalies, anorectal malformations).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: PEG 3350	Drug: PEG 3350; Patients assigned to the PEG group will receive age-based dosing according to standard clinical guidelines, with flexibility for dosing adjustments. Each container will contain an identical white powder and a measuring spoon. One measuring spoon will contain 17g of PEG. Initial dosing will be according to age groups as follows: 4-7 years: ½ spoon, once daily; 8-18 years: 1 spoon, once daily
Active Comparator: Senna	Dietary supplement: Senna; Patients assigned to the Senna group will receive age-based dosing, in line with standard clinical guidelines and clinical practice. Dosing adjustments will be permitted and encouraged throughout the trial based on physician judgment at clinical visits or family-initiated requests. Each container will contain an identical white powder and a measuring spoon. One measuring spoon will contain 20mg of Senna. Initial dosing will be according to age groups as follows: 4-7 years: ½ spoon, once daily; 8-18 years: 1 spoon, once daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of fecal incontinence incidents per week at 3 months	Mean number of fecal incontinence episodes per week at 3 months of treatment. A prospective 7-day diary will be completed by the family, at enrollment and before each monthly visit. The 3-month clinic meeting diary will be used to measure this outcome.	At 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement in patient-initiated toilet-sitting	Improvement in patient-initiated toilet-sitting: To understand changes in bowel habits, the study will distinguish between parent-initiated toilet sitting ("it's time to go to the bathroom/I think you need to poop") and patient-initiated toilet sitting ("I need to go!"). Changes in the number of patient-initiated sittings/week throughout the study will be compared between both treatments.	At 3 months
Proportion of patients achieving 0-1 fecal incontinence episodes per week.		At 3 months
Proportion of patients achieving any improvement (≥1 episode/week reduction)		At 3 months
Number of enemas used during the 3-month period		From enrollment till 3 months
Proportion of patients experiencing mild versus moderate-to-severe abdominal pain or cramping (classified by physician and family report).		From enrollment till 3 months
Parent-reported satisfaction with treatment (measured on a 5-point Likert scale: Very Satisfied to Very Dissatisfied).		At 3 months
Family impression of overall improvement (measured on a 5-point Likert scale)		At 3 months
Proportion of patients still meeting Rome IV criteria for functional constipation		At 3 months
Compliance Assessment: Compliance with assigned treatment will be assessed based weighing the medication containers: Classification as "good compliance" (>80% doses taken) versus "poor compliance" (<80%)		From enrollment till 3 months

Collaborators and Investigators

• Sponsor: Shaare Zedek Medical Center
• Collaborators: Assaf-Harofeh Medical Center

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): January 1, 2028

Study Registration Dates

• First Submitted: May 17, 2026
• First Submitted That Met QC Criteria: May 17, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 17, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Functional constipation; Retentive encoperesis; Encoperesis
• Additional Relevant MeSH Terms: Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Carbohydrates; Polycyclic Aromatic Hydrocarbons; Hydrocarbons, Aromatic; Polycyclic Compounds; Glycosides; Senna Extract; Anthraquinones; Anthrones; Anthracenes; Quinones; Plant Extracts; Plant Preparations; Biological Products; Complex Mixtures; Sennosides; polyethylene glycol 3350
• Other Study ID Numbers: Senna vs PEG

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No