Abdominal Neuromuscular Electrical Stimulation to Treat Neurogenic Bowel Dysfunction in Chronic SCI (ESBo-SCI)

ESBo-SCI: Abdominal Neuromuscular Electrical Stimulation to Treat Neurogenic Bowel Dysfunction in Chronic SCI

Difficulty with bowel movements is one of the most serious side effects of spinal cord injury and one that most severely restricts everyday life. Many people affected take 30 to 60 minutes, or considerably longer, to pass stools. This is accompanied by a significantly slowed bowel transit, which often leads to a feeling of fullness, flatulence and chronic pain. The study investigates a method suitable for everyday use to support bowel function: electrical stimulation of the abdominal muscles. This involves applying adhesive electrodes to the abdomen and controlling them via a small device. The treatment is carried out independently at home - 30 minutes before each planned bowel movement. Two stimulation settings are being compared: i) Motor stimulation: The current strength causes a noticeable contraction of the abdominal muscles. ii) Sensory stimulation: The intensity is lower and is perceived merely as a gentle tingling sensation. The procedure is divided into several phases. Before stimulation begins, baseline values are recorded during a two-week pre-observation phase. Subsequently, both stimulation methods are applied one after the other for 12 weeks each, interspersed with a six-week break without stimulation. Which participant starts with which type of stimulation is determined at random. A final six-week follow-up phase assesses whether any improvements achieved persist after the end of treatment.

During the study, participants will keep a diary and, together with specialists, complete two questionnaires. Bowel transit time will be measured in a simple and safe manner (using maize grains and a capsule containing blue food colouring). In addition, stool samples will be collected at five specified time points to analyse changes in the gut microbiota. The aim is to evaluate a gentle, practical method that facilitates the bowel movement process, promotes gut health and noticeably improves the quality of life of people with spinal cord injury.

Study Overview

• Status: Not yet recruiting
• Conditions: Spinal Cord Injuries (Complete and Incomplete)
• Intervention / Treatment: Other: Motor NMES Modality; Other: Sensory NMES Modality

Detailed Description

Neurogenic Bowel Dysfunction (NBD) is a debilitating complication affecting the majority of individuals with spinal cord injury (SCI), resulting from disrupted autonomic and somatic neural pathways regulating colonic peristalsis and sphincter control. Clinically, NBD manifests as prolonged defecation routines, severe constipation, fecal incontinence, and abdominal distension, with approximately 55% of individuals reporting moderate to severe deterioration in quality of life due to restrictive routines, anxiety over accidental episodes, and caregiver dependency. In severe cases, bowel management requires several hours each day and represents a leading source of secondary morbidity and hospital readmission. In addition, prolonged gastrointestinal transit in SCI alters the gut luminal environment, causing mucosal dysbiosis, depletion of beneficial short-chain fatty acid-producing taxa, and accumulation of potentially deleterious proteolytic fermentation metabolites.

Neuromuscular electrical stimulation (NMES) applied to the abdominal wall musculature is a non-invasive intervention designed to improve bowel function. Historically, abdominal NMES has been applied at suprathreshold intensities to trigger visible tetanic muscle contractions, based on the premise that increased intra-abdominal pressure mechanically facilitates colonic transit and defecation. However, pilot findings and emerging neurophysiological data indicate that sub-motor (sensory) stimulation may independently modulate autonomic enteric pathways via afferent sensory signaling to the spinal cord. In a preliminary single-center pilot trial (NCT04914975, N = 20), daily home-based abdominal NMES applied for 30 minutes prior to scheduled bowel care significantly reduced defecation time and whole-gut transit time. Notably, participants with neurological injury levels below T12 who possessed intact voluntary abdominal motor control also derived clinical benefits, indicating that the underlying mechanisms extend beyond mechanical efferent activation to include sensory afferent neuromodulation.

The ESBo-SCI trial is a randomized, active-controlled, two-period cross-over clinical trial designed to compare the clinical and physiological efficacy of motor-level versus sensory-level abdominal NMES in individuals with chronic SCI. The protocol spans an overall duration of 38 weeks. Following a 2-week standardized baseline phase of prospective documentation without electrical stimulation, participants complete a 12-week intervention period (Stimulation Block I) with either motor NMES or sensory NMES as determined by randomization. This is followed by a 6-week washout phase without electrical stimulation to eliminate potential carry-over effects. Participants then cross over to the alternate stimulation modality for a second 12-week intervention period (Stimulation Block II), concluding with a 6-week follow-up observation phase to determine the durability and persistence of treatment effects. Throughout both 12-week intervention blocks, participants self-administer the stimulation at home for 30 minutes immediately preceding their scheduled bowel routine using certified, current-controlled clinical stimulators. Electrical current intensity is individualized through on-site threshold testing prior to initiating each stimulation block. The motor threshold is defined as the lowest current intensity eliciting a visible muscle twitch within the stimulated area. For the sensory NMES modality, the current amplitude is fixed at 10% below this motor threshold, ensuring activation of cutaneous and subcutaneous sensory afferents without triggering visible muscle contraction. For the motor NMES modality, current amplitude is adjusted above the motor threshold to evoke visible, robust, tetanic abdominal muscle contractions that remain comfortable and tolerable to the participant.

Participants are randomized in a 1:1 allocation to determine the sequence of interventions (motor NMES first versus sensory NMES first).

Laboratory personnel and statisticians remain blinded to treatment sequence and stimulation modality. Participants are masked to the primary study hypotheses and sequence allocation, remaining uninformed regarding which stimulation mode is hypothesized to be superior. The primary hypothesis posits that motor NMES produces a significantly greater reduction in defecation time than sensory NMES, mediated primarily by mechanical intra-abdominal pressure generation combined with efferent motor contractions. The mechanistic hypothesis posits that if sensory NMES yields equivalent or superior clinical improvements, therapeutic benefits will be attributed primarily to afferent somatosensory neuromodulation acting on autonomic spinal and enteric circuits.

A total target enrollment of 41 participants is planned to account for anticipated attrition and provide 33 evaluable participants, ensuring statistical power to detect a clinically meaningful difference in defecation time. Differences between stimulation modalities and study phases will be analyzed using repeated-measures linear mixed-effects models with a random intercept for individual participants, treating the first week of each intervention block as an accommodation run-in phase. All prospective participant logs and clinical questionnaires are managed through an encrypted, web-based electronic data capture system using dedicated tablet computers.

• Study Type: Interventional
• Enrollment (Estimated): 41
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ines Bersch, PhD; Phone Number: +41 41 939 4206; Email: ines.bersch@paraplegie.ch
• Study Contact Backup: Name: Kathrin Schafer, MPH; Phone Number: +41 41 939 4334; Email: kathrin.schafer@paraplegie.ch

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T5J4P6
      • University of Alberta
      • Contact: Chester Ho, Prof; Phone Number: (780) 492-4388; Email: chho@ualberta.ca
      • Contact: Dirk Everaert, PhD; Email: everaert@ualberta.ca
      • Sub-Investigator: Chester Ho, Prof
• Norway
  • Oslo
    • Oslo, Oslo, Norway, 1453
      • Sunnaas Rehabilitation Hospital
      • Contact: Anne Catrine Martinsen, Prof; Phone Number: +47 99 21 65 66; Email: Anne.Catrine.Traegde.Martinsen@sunnaas.no
      • Contact: Thomas Glott, MD; Email: Thomas.Glott@sunnaas.no
      • Sub-Investigator: Anne Catrine Martinsen, Prof
• Switzerland
  • Canton of Lucerne
    • Nottwil, Canton of Lucerne, Switzerland, 6207
      • Swiss Paraplegic Center Nottwil
      • Contact: Ines Bersch, PhD; Phone Number: +41 41 939 4206; Email: ines.bersch@paraplegie.ch
      • Contact: Kathrin Schafer, MPH; Phone Number: +41 41 939 4334; Email: kathrin.schafer@paraplegie.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Traumatic or non-traumatic spinal cord injury.
• Neurological level of injury C1 to L5.
• American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade A, B, C, or D.
• Chronicity ≥1 year post-injury.
• Age ≥18 years.
• Documented defecation time >30 minutes per routine with an expressed desire to reduce time spent on bowel care.
• Established and stable conservative bowel management protocol.
• Signed informed consent

Exclusion Criteria:

• Active chronic inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis).
• Concurrent regular opioid therapy.
• Active malignant disease in the abdominal or pelvic region.
• Patients currently undergoing primary acute rehabilitation.
• Presence of an implanted sacral anterior root stimulator (Brindley stimulator).
• Prior surgical diversion of the gastrointestinal tract (e.g., colostomy, ileostomy).
• Pregnancy (confirmed via urine pregnancy test in females of childbearing potential aged 18-49 years).
• Open skin lesions or active dermatological defects at designated electrode placement sites.
• Exacerbation of severe autonomic dysreflexia provoked during electrical stimulation testing.
• Inability to comply with study protocols or operate the device due to substantial cognitive deficits or language barriers.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Sensory NMES Modality; Stimulation is delivered via two independent channels using four self-adhesive surface electrodes placed bilaterally across the abdominal wall over the rectus abdominis and external oblique muscles. Stimulation is administered with a symmetrical rectangular biphasic current, 40 Hz, 300 µs. Threshold testing is performed at on-site visits prior to initiating each stimulation block: Motor Threshold Definition: The lowest electrical current intensity eliciting a visible muscle twitch within the stimulated abdominal area. In this modality, the sensity modality, the current amplitude is fixed at 10% below the individually determined motor threshold, ensuring activation of cutaneous and subcutaneous sensory afferents without triggering visible muscle contraction. Participants will stimulate with their individually determined amplitude.	Other: Motor NMES Modality; Stimulation is delivered via two independent channels using four self-adhesive surface electrodes (5 cm × 9 cm; Axelgaard PALS) placed bilaterally across the abdominal wall over the rectus abdominis and external oblique muscles.; Current Type: Symmetrical rectangular biphasic current.; Frequency: 40 Hz.; Pulse Duration: 300 microseconds (µs).; Duty Cycle: 8 seconds ON (incorporating 2 seconds ramp-up and 2 seconds ramp-down) followed by 3 seconds OFF. Motor NMES Modality: Current amplitude is adjusted above motor threshold to evoke a visible, robust, tetanic abdominal muscle contraction that remains comfortable and tolerable to the participant.
Active Comparator: Motor NMES Modality; Stimulation is delivered via two independent channels using four self-adhesive surface electrodes (5 cm × 9 cm; Axelgaard PALS) placed bilaterally across the abdominal wall over the rectus abdominis and external oblique muscles. Current Type: Symmetrical rectangular biphasic current. Frequency: 40 Hz. Pulse Duration: 300 microseconds (µs). Duty Cycle: 8 seconds ON (incorporating 2 seconds ramp-up and 2 seconds ramp-down) followed by 3 seconds OFF. In this modality, the motor NMES modality, the current amplitude is adjusted above motor threshold to evoke a visible, robust, tetanic abdominal muscle contraction that remains comfortable and tolerable to the participant. Participants will stimulate with their individually determined amplitude, that is above the sensory threshold.	Other: Sensory NMES Modality; Stimulation is delivered via two independent channels using four self-adhesive surface electrodes (5 cm × 9 cm; Axelgaard PALS) placed bilaterally across the abdominal wall over the rectus abdominis and external oblique muscles.; Current Type: Symmetrical rectangular biphasic current.; Frequency: 40 Hz.; Pulse Duration: 300 µs. Threshold testing is performed at on-site visits prior to initiating each stimulation block: Motor Threshold Definition: The lowest electrical current intensity eliciting a visible muscle twitch within the stimulated abdominal area.; Sensory NMES Modality: Current amplitude is fixed at 10% below the individually determined motor threshold, ensuring activation of cutaneous and subcutaneous sensory afferents without triggering visible muscle contraction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Defecation time	Defined as the elapsed duration from the expulsion of the first stool until the expulsion of the last stool. Participants prospectively record precise timestamps for each bowel routine in a daily electronic diary. The primary endpoint is the intra-individual change in mean weekly defecation time between baseline and the two stimulation modalities (excluding the first week of each stimulation block as a run-in phase).	Defecation time will be assessed with a stool diary over the entire study period of 38 week depending on the bowel movements per week.
Defecation Time (Minutes)	Defined as the elapsed duration from the expulsion of the first stool until the expulsion of the last stool. Participants prospectively record precise timestamps for each bowel routine in a daily electronic diary. The primary endpoint is the intra-individual change in mean weekly defecation time between baseline and the two stimulation modalities (excluding the first week of each stimulation block as a run-in phase).	Defecation will be assessed in form of a diary over the entire study period of 38 weeks depending on the number of defecation sessions per week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whole-Gut Transit Time (WGTT)	Evaluated using a validated home test administered prior to study visits: Standardized Blue Dye Test: Following an overnight fast (≥8 hours), participants ingest two plain rice crackers and swallow a single 0.68 mL gelatin capsule containing 0.25 g food-grade blue dye powder (~60 mg combined E131/E132; Hollinger Farbpulver Blau) with ~100 mL water. Diet, activity, and bowel medications remain unchanged, with intensely colored foods avoided for 48 hours. WGTT is defined as the duration between capsule ingestion and the first appearance of blue or blue-green stool.	The Blue Dye Test will performed 5 times over the entire study period of 38 weeks.
Whole-Gut Transit Time (WGTT)	Evaluated using a validated home test administered prior to study visits: Corn Test: Ingestion of 140 g of canned sweetcorn; elapsed time to the first visual identification of excreted corn kernels is recorded.	The Corn Test will performed 5 times over the entire study period of 38 weeks.
Stool Consistency	Bristol Stool Form Scale (BSFS; range: Type 1 [separate hard lumps] to Type 7 [entirely liquid]), logged per defecation event	The BSFS is included in the stool diary and will be filled in at the every defecation time point over the entire study period of 38 weeks.
Neurogenic Bowel Dysfunction (NBD) Score	Validated 10-item clinical questionnaire assessing fecal incontinence, constipation, defecation duration, medication dependence, and lifestyle restriction (total score 0 to 47; higher scores indicate greater severity).	The NBD score will be assessed 5 times over the entire study period of 38 weeks.
Gastrointestinal Quality of Life Index (GIQLI)	Total Score Range: 0 to 144 points (derived from 36 items, each rated on a 5-point Likert scale from 0 to 4). Higher scores indicate a better quality of life, meaning fewer symptoms and better daily functioning. Disease-specific health-related quality of life instrument evaluating gastrointestinal symptoms, physical functioning, emotional state, social performance, and medical treatment burden.	The GIQLI will be assessed 5 times over the entire study period of 38 weeks.
Gut Microbiome Profiling	Fecal samples are collected at scheduled visits using ambient-temperature DNA stabilization kits (DNA Genotek) or home frozen at -20°C prior to transport on cold packs and storage at -80°C. Stool aliquots undergo enzymatic pre-lysis and bead-beating prior to silica-membrane DNA purification. Full-length 16S rRNA genes (V1-V9 regions, ~1.5 kb) are amplified (primers 27F/1492R) and sequenced on Oxford Nanopore MinION platforms. Sequences are demultiplexed, filtered (Q ≥ 10; 1,400-1,650 bp), and taxonomically classified against the SILVA 138 database to quantify alpha/beta diversity and relative abundance of short-chain fatty acid-producing versus inflammation-associated taxa.	The Gut Microbiome Profiling consisting of stool probes will be assessed 5 times over the entire study period of 38 weeks.
Defecation Diary Metrics-absolut defecation time	Daily tracking includes time of routine initiation, first stool expulsion, last stool expulsion as the absolute defecation time.	The diary will be filled in electronically on daily base over the entire study period of 38 weeks.
Defecation Diary Metrics-relative defecation time	Daily tracking includes time of clean-up start and completion to calculate the relative defecation time.	The diary will be filled in electronically on daily base over the entire study period of 38 weeks.
Defecation Diary Metrics-rountinely defecation interventions	Daily tracking includes time of individual defecation interventions	The diary will be filled in electronically on daily base over the entire study period of 38 weeks.
Defecation Diary Metrics-stimulation parameter	The diary includes the stimulation parameter in terms of intensity (amplitude mA)	The stimulation parameter will be filled in electronically during the two stimulation periods of 12 weeks each.
Defecation Diary Metrics-stimulation time	The diary includes the stimulation time (minutes)	The stimulation parameter will be filled in electronically during the two stimulation periods of 12 weeks each.
Defecation Diary Metrics-stimulation posture	The diary includes participants' posture during stimulation	The stimulation parameter will be filled in electronically during the two stimulation periods of 12 weeks each.
Nutritional Confounders	Dietary intake is assessed by using the Cambridge Food Frequency Questionnaire (FFQ).	The Nutritional Confounders will be assessed twice at baseline (day 1) and at study completion (day 1-3, week 38).
Lifestyle Confounder frequency of physical activity	Frequency of weekly physical activity will be documented	This Lifestyle Confounder will be assessed twice at baseline (day 1) and at study completion (day 1-3, week 38).
Lifestyle Confounder duration of physical activity	Duration of weekly physical activity will be documented	This Lifestyle Confounder will be assessed twice at baseline (day 1) and at study completion (day 1-3, week 38).
Lifestyle Confounder type of physical activity	Type of weekly physical activity will be documented	This Lifestyle Confounder will be assessed twice at baseline (day 1) and at study completion (day 1-3, week 38).

Collaborators and Investigators

• Sponsor: Swiss Paraplegic Research, Nottwil
• Investigators: Principal Investigator: Ines Bersch, PhD, Swiss Paraplegic Research, Nottwil

Publications and helpful links

General Publications

• Bersch I, Schafer K, Limacher A, Sonntag U, Baumberger M, Alberty M. The effect of neuromuscular electrical stimulation on bowel management in people with chronic spinal cord injury-An IDEAL 2a pilot study. Colorectal Dis. 2025 Nov;27(11):e70276. doi: 10.1111/codi.70276.

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): December 31, 2030

Study Registration Dates

• First Submitted: October 8, 2026
• First Submitted That Met QC Criteria: November 5, 2026
• First Posted (Actual): November 10, 2026

Study Record Updates

• Last Update Posted (Actual): November 10, 2026
• Last Update Submitted That Met QC Criteria: November 5, 2026
• Last Verified: October 1, 2026

More Information

Terms related to this study

• Keywords: neuromuscular electrical stimulation; microbiome; gastrointestinal health; neurogenic bowel dysfunction; bowel management
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Trauma, Nervous System; Spinal Cord Diseases; Spinal Cord Injuries
• Other Study ID Numbers: 2026-01772; 10.007.423 (Other Grant/Funding Number: Swiss National Science Foundation)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No