Obesity on the Efficacy of Bilateral Tibial Nerve Stimulation

Impact of Obesity on the Efficacy of Bilateral Tibial Nerve Stimulation in Obstructed Defecation

Obstructed defecation syndrome (ODS) is a common functional bowel disorder characterized by difficulty in stool evacuation. Bilateral posterior tibial nerve stimulation (BT PTNS) has emerged as a noninvasive, safe, and effective therapeutic option for functional ODS, improving symptom severity and quality of life.

Study Overview

• Status: Completed
• Conditions: Obstructed Defecation
• Intervention / Treatment: Procedure: Bilateral posterior tibial nerve stimulation

Detailed Description

Obesity is associated with altered pelvic floor mechanics, which may affect the response to neuromodulation therapy. However, the effect of obesity on BT PTNS outcomes in ODS has not been systematically evaluated. This study aims to fill this knowledge gap by comparing treatment efficacy between obese and non-obese patients.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Alexandria, Egypt, 21531
    • The surgical department of Medical Research Institute Hospital, Alexandria University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of functional obstructed defecation (Rome IV criteria).
• Able to provide informed consent.
• BMI ≥30 kg/m² (obese group) or BMI <30 kg/m² (non-obese group).

Exclusion Criteria:

• Organic causes of constipation (e.g., colorectal cancer, inflammatory bowel disease).
• Previous pelvic floor surgery.
• Neurological disorders affecting bowel function.
• Pregnancy or lactation.
• Current use of other neuromodulation therapies.

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: obese with ODS; BT PTNS in obese patients with ODS	Procedure: Bilateral posterior tibial nerve stimulation; Procedure: BT PTNS will be administered via transcutaneous electrodes placed bilaterally along the posterior tibial nerve at the medial malleolus.; Frequency: 3 sessions per week for 6 weeks (total of 18 sessions).; Duration per Session: 30 minutes.; Monitoring: Patients will be monitored for adverse events during and after each session.
Active Comparator: Non obese with ODS; BT PTNS in non-obese patients with ODS	Procedure: Bilateral posterior tibial nerve stimulation; Procedure: BT PTNS will be administered via transcutaneous electrodes placed bilaterally along the posterior tibial nerve at the medial malleolus.; Frequency: 3 sessions per week for 6 weeks (total of 18 sessions).; Duration per Session: 30 minutes.; Monitoring: Patients will be monitored for adverse events during and after each session.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in symptom severity measured by the Modified Obstructed Defecation Score (MODS).	Scale range: 0 to 24 Interpretation: Higher scores indicate more severe obstructed defecation symptoms Unit of measure: Units on a validated symptom severity scale. No aggregation of different measurements into a single reported value is performed. Each scale is analyzed independently. In response to the Advisory Issue, we have included the unabbreviated titles of the scales, their minimum and maximum values, and clarified whether higher scores represent better or worse outcomes for each outcome measure.	Within 6 weeks of treatment.
Change in quality of life measured by the Patient Assessment of Constipation Quality of Life questionnaire (PAC-QOL).	Scale range: 0 to 96 Interpretation: Higher scores indicate worse constipation-related quality of life Unit of measure: Mean score on a validated quality-of-life scale No aggregation of different measurements into a single reported value is performed. Each scale is analyzed independently. In response to the Advisory Issue, we have included the unabbreviated titles of the scales, their minimum and maximum values, and clarified whether higher scores represent better or worse outcomes for each outcome measure.	Within 6 weeks of treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pelvic floor function	To assess the impact of obesity on pelvic floor function using electromyography (EMG). Electromyograpghy (EMG) a diagnostic test that evaluates the electrical signals between your nerves and muscles to check for neuromuscular problems like nerve damage or muscle diseases. It usually involves two parts: a nerve conduction study (NCS) using surface electrodes to measure nerve signal speed, and a needle EMG where a tiny needle electrode is inserted into a muscle to record its activity at rest and during contraction, revealing abnormalities. To assess amplitude, number of turns and duration of pelvic floor muscle.	Within 6 weeks of treatment.

Collaborators and Investigators

• Sponsor: General Committee of Teaching Hospitals and Institutes, Egypt

Study record dates

Study Major Dates

• Study Start (Actual): February 15, 2026
• Primary Completion (Actual): March 25, 2026
• Study Completion (Actual): March 28, 2026

Study Registration Dates

• First Submitted: December 23, 2025
• First Submitted That Met QC Criteria: February 2, 2026
• First Posted (Actual): February 5, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Obstructed Defecation; ODS; Bilateral Tibial Nerve Stimulation; BT PTNS
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity
• Other Study ID Numbers: obesity and ODS

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