Effect of Low Level Laser Therapy on Women With Obstructive Defecation Syndrome

August 13, 2026 updated by: Doaa A. Osman, Cairo University

Effect of Low Level Laser Therapy on Women With Obstructive Defecation Syndrome: A Randomized Controlled Trial

Obstructive defecation syndrome (ODS) is a condition in which a person has difficulty completely emptying the rectum during bowel movements. Women with ODS may experience excessive straining, a feeling of incomplete evacuation or blockage, abdominal discomfort, and the need to use manual assistance, laxatives, or enemas to facilitate defecation.

This randomized controlled trial will investigate the effect of adding low-level laser therapy (LLLT) to a conventional treatment program for women with ODS. Participants will be randomly assigned to one of two groups. The control group will receive nutritional modification and biofeedback training, while the study group will receive the same treatment in addition to low-level laser therapy applied to the lumbosacral region.

The study will evaluate whether adding low-level laser therapy can improve anorectal function, reduce the severity of ODS symptoms, and improve health-related quality of life compared with conventional treatment alone.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a prospective, randomized, pre-posttest controlled trial designed to investigate the effect of low-level laser therapy (LLLT) as an adjunct to conventional treatment in women with obstructive defecation syndrome (ODS).

Women diagnosed with ODS will be randomly assigned to two groups. Participants in the control group will receive nutritional modification and biofeedback training. Nutritional modification will focus on dietary fiber intake, adequate hydration, and weight-management recommendations. Biofeedback training will provide real-time feedback to facilitate appropriate pelvic floor muscle control, relaxation, and coordination during defecation.

Participants in the study group will receive the same nutritional modification and biofeedback program in addition to low-level laser therapy. LLLT will be applied to the lumbosacral region, targeting the lumbar (L2-L5) and sacral (S1-S5) areas.

Participants will be assessed before and after the intervention. Anorectal manometry will be used to evaluate anorectal physiological parameters, including anal resting pressure, squeeze pressure, strain pressure, endurance, rectal sensitivity, and rectal compliance. The severity of obstructive defecation symptoms will be evaluated using the Renzi Obstructive Defecation Syndrome Score, and health-related quality of life will be assessed using the Short Form-36 Health Survey (SF-36).

The study aims to determine whether adding low-level laser therapy to nutritional modification and biofeedback training provides additional benefits in anorectal function, ODS symptom severity, and quality of life compared with nutritional modification and biofeedback training alone.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

  • Name: Radwa Ayad Mohamed, M.Sc

Study Locations

  • Egypt
      • Giza, Egypt
        • Faculty of physical therapy, Cairo University
        • Contact:
        • Contact:
          • Radwa Ayad Mohamed, M.Sc

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Woman diagnosed with ODS according to the Renzi ODS score (≥ 9).
  • They suffer from difficult defecation for at least three months.
  • Their ages will range from 30-45 years old.
  • Their body mass index (BMI) will range from 25-30 kg/m2.
  • Their parity number will be 2-3 times.

Exclusion Criteria:

  • Any abnormalities around cancer colon, interstitial cystitis, or endometriosis.
  • Enlarged rectal diameter and damaged mienteric plexus and abnormal motor function of rectum.
  • Psychological or mental health problems.
  • Pregnancy and lactation
  • A history of previous pelvic surgery.
  • A history of retinopathy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Nutritional modification + Biofeedback muscle training
It will consist of 20 women with Obstructive Defecation Syndrome. They will be treated by nutritional modification and biofeedback muscle training, twice weekly for 8 weeks.
Other: Nutritional Modification
Participants will receive nutritional modification throughout the intervention period. The program will include a fiber-rich diet containing both soluble and insoluble fiber to improve stool consistency and facilitate bowel movements. Participants will also be instructed to maintain adequate hydration by consuming approximately 6-8 glasses of water per day. The nutritional modification program will be applied to participants in both the control and study groups.
Other: Biofeedback Training
Participants will receive anorectal biofeedback training using a rectal biofeedback device that provides real-time visual or auditory feedback on pelvic floor muscle activity. During each session, participants will be trained to improve pelvic floor muscle coordination and relaxation during simulated defecation. They will be instructed to consciously relax and release the pelvic floor muscles, use deep abdominal breathing, and practice relaxation techniques while observing the biofeedback signals. Exercises will be repeated approximately 10-20 times per session according to participant tolerance and therapist assessment. The intervention will be administered twice weekly.
Experimental: Low level laser therapy + Nutritional modification + Biofeedback muscle training
It will consist of 20 women with Obstructive Defecation Syndrome. They will be treated by the same nutritional modification and biofeedback muscle training, in addition to low level laser therapy, twice weekly for 8 weeks.
Other: Nutritional Modification
Participants will receive nutritional modification throughout the intervention period. The program will include a fiber-rich diet containing both soluble and insoluble fiber to improve stool consistency and facilitate bowel movements. Participants will also be instructed to maintain adequate hydration by consuming approximately 6-8 glasses of water per day. The nutritional modification program will be applied to participants in both the control and study groups.
Other: Biofeedback Training
Participants will receive anorectal biofeedback training using a rectal biofeedback device that provides real-time visual or auditory feedback on pelvic floor muscle activity. During each session, participants will be trained to improve pelvic floor muscle coordination and relaxation during simulated defecation. They will be instructed to consciously relax and release the pelvic floor muscles, use deep abdominal breathing, and practice relaxation techniques while observing the biofeedback signals. Exercises will be repeated approximately 10-20 times per session according to participant tolerance and therapist assessment. The intervention will be administered twice weekly.
Device: Low Level Laser Therapy
Participants in the study group will receive low-level laser therapy (LLLT) using a Scanner Laser PR 999 4W device with dual wavelengths (continuous 808 nm and pulsed 940 nm). LLLT will be applied to the lumbosacral region, targeting the lumbar (L2-L5) and sacral (S1-S5) areas. Participants will be positioned prone, and the laser scanner will be applied perpendicular to the skin at a 90° angle, approximately 1-2 inches above the treatment area. The scanner will be moved slowly to provide uniform coverage of the lumbosacral region. Each treatment session will last 30 minutes and will be administered twice weekly for 8 weeks. Both participants and therapists will wear appropriate protective eyewear during treatment.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Obstructive Defecation Syndrome Severity Assessed by the Renzi ODS Score
Time Frame: 8 weeks
The severity of obstructive defecation syndrome (ODS) will be assessed using the Renzi ODS Score. The scale consists of five items assessing excessive straining, incomplete rectal evacuation, use of enemas and/or laxatives, vaginal-anal-perineal digitations, and abdominal discomfort and/or pain. The total score ranges from 0 to 20, with higher scores indicating greater severity of ODS symptoms. A score of ≥9 is used to identify ODS.
8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Anal Resting Pressure Assessed by Anorectal Manometry
Time Frame: 8 weeks
Anal resting pressure will be assessed using anorectal manometry. After insertion of the anorectal manometry probe, the participant will be allowed to relax for approximately 3-5 minutes to allow anal sphincter tone to return to baseline. Basal anal pressure will then be recorded at rest over 60 seconds. The outcome will be expressed in mmHg.
8 weeks
Anal Squeeze Pressure Assessed by Anorectal Manometry
Time Frame: 8 weeks
Anal squeeze pressure will be assessed using anorectal manometry during voluntary contraction of the anal sphincter and pelvic floor muscles. Participants will perform three maximum voluntary squeezes, each maintained for approximately 5 seconds, with a 30-second recovery period between attempts. The average pressure obtained from the three attempts will be used for analysis and expressed in mmHg.
8 weeks
Anal Strain Pressure Assessed by Anorectal Manometry
Time Frame: 8 weeks
Anal strain pressure will be assessed using anorectal manometry during simulated defecation. Participants will be instructed to perform a bearing-down maneuver to simulate defecation. Three straining attempts will be performed, with each attempt lasting approximately 15 seconds and separated by a 30-second recovery interval. The average pressure obtained from the three attempts will be used for analysis and expressed in mmHg.
8 weeks
Anal Sphincter Endurance Assessed by Anorectal Manometry
Time Frame: 8 weeks
Anal sphincter endurance will be assessed using anorectal manometry during a sustained maximum voluntary contraction. Endurance will be defined as the length of time for which the participant can maintain pressure during the maximum voluntary contraction. The outcome will be recorded in seconds, with a longer duration indicating greater ability to sustain the contraction.
8 weeks
Rectal Sensitivity Assessed by Anorectal Manometry
Time Frame: 8 weeks
Rectal sensitivity will be assessed using graded balloon distension during anorectal manometry. Participants will be instructed to report the first rectal sensation, desire or urgency to defecate, and maximum tolerated sensation during progressive balloon inflation. The corresponding balloon volumes will be recorded in milliliters (mL). Lower sensory threshold volumes indicate greater rectal sensitivity, whereas higher threshold volumes indicate reduced rectal sensitivity.
8 weeks
Rectal Compliance Assessed by Anorectal Manometry
Time Frame: 8 weeks
Rectal compliance will be assessed during anorectal manometry using controlled rectal balloon distension. Compliance will be determined from the relationship between changes in balloon volume and corresponding changes in steady-state intrarectal pressure (ΔV/ΔP). Higher values indicate greater rectal distensibility, whereas lower values indicate greater resistance to rectal distension.
8 weeks
Health-Related Quality of Life Assessed by the Short Form-36 Health Survey (SF-36)
Time Frame: 8 weeks
Health-related quality of life will be assessed using the 36-item Short Form Health Survey (SF-36). The questionnaire evaluates eight health domains: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. Each domain is scored from 0 to 100, with higher scores indicating a more favorable health status.
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cairo University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Mohamed Ahmed Mohamed Awad, PhD, Professor, Cairo University
  • Study Director: Doaa A. Osman, PhD, Ass. Professor, Cairo University
  • Study Director: Hesham Mahmoud Salah El-Din, PhD, Professor, Cairo University
  • Principal Investigator: Radwa Ayad Mohamed, M. Sc, PhD Student, Cairo University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 20, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 20, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 13, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 13, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • P.T.REC/012/006002

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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