Combined Lactulose H2-breath Test With Abdominal Imaging

NCT07145580 | Recruiting

• 1 other identifier: KlinikArlesheim
• Study Type: observational
• Target: 500
• Locations: 1 country
• Sites: 1

Brief Summary

Hydrogen (H₂) breath tests serve several purposes. (i) detect malabsorption of carbohydrates such as lactose and fructose, (ii) measurement of oro-caecal transit time (iii) associate hydrogen production with the onset of abdominal symptoms like bloating, flatulence, pain, and diarrhea (which indicates carbohydrate intolerance), and (iv) diagnose small intestinal bacterial overgrowth (SIBO). It is important to distinguish between carbohydrate intolerance and SIBO because their treatments differ significantly. Carbohydrate intolerance is typically managed through dietary restrictions, while SIBO requires antibiotic therapy. However, recent guidelines have questioned the accuracy of hydrogen breath tests in diagnosing SIBO due to variability in OCTT measurements. This limitation can be addressed by combining H₂ breath tests with imaging techniques such as scintigraphy, which independently confirm OCTT. When this combined approach is used, SIBO is diagnosed if the rise in breath H₂ occurs before the contrast agent appears in the large bowel. Despite its benefits, this combined method faces organizational and financial challenges that limit its routine clinical use. This retrospective cohort study aims to assess the clinical performance of a cheap and simple test that combines a 20g lactulose H₂ breath test with simple radiographic abdominal imaging to assess OCTT, SIBO, and carbohydrate tolerance. The novel innovation in this method is to confirm oro-caecal transit by taking an X-ray of the abdomen when H₂ production increases during the examination. If the contrast agent is not visible in the cecum when H₂ rises, this indicates the presence of SIBO. Conversely, if the contrast agent is present in the cecum at that time, it confirms normal OCTT, and any abdominal symptoms occurring after this point support a diagnosis of carbohydrate intolerance. If the method is proven to be valid, then this simple test will greatly facilitate the accurate diagnosis of SIBO and carbohydrate intolerance, allowing for more appropriate treatment decisions.

Conditions

Food Intolerance Syndromes; Small Intestinal Bacterial Overgrowth Syndrome (SIBO); Breath Tests

Keywords

Irritable bowel syndrome (IBS); Functional bloating; Functional Diarrhea; Food Intolerance Syndromes; Small intestinal bacterial overgrowth syndrome (SIBO); Hydrogen Breath Test

Outcome Measures

Primary Outcomes (1)

• Practicability and safety of the novel. concurrent 20g lactulose H2 breath test with abdominal imaging

  This pilot feasibility study will report the practicability and safety of the concurrent 20g lactulose H2 breath test with abdominal imaging, defined as: * Practicability / Technical success in performance of the investigation defined by (i) correct documentation of H2 production and patient symptoms using validated questionnaires (ii) timely acquisition of abdominal imaging within 20 min of H2 increase after test substance ingestion (both expressed as percentage ot total) . * Safety of the concurrent 20g lactulose H2 breath test with abdominal imaging, defined as the ability of patients (i) to ingest the test substrate (400ml) without nausea and vomiting (ii) to complete the 3-hour operating procedure without severe abdominal symptoms that require medical treatment and / or termination of test (both expressed as percentage ot total). The primary outcome measures are descriptive and not chosen to demonstrate superiority of this methodology compared to existing techniques.

  3 hours

Secondary Outcomes (2)

• Inter-rater agreement of the oro-caecal transit time

  3-hours

• Assess prevalence of food intolerance and SIBO in patients referred for breath testing

  3-hours

Other Outcomes (1)

• Exploratory analysis of causes of abdominal symptoms during lactulose hydrogen breath test

  3-hours

Study Arms (1)

Patients referred for hydrogen breath testing

Adult patients referred for hydrogen breath testing between 2020 and 2024 were included in this cohort. All patients included in the analysis signed general consent for the use of anonymized clinical data in studies. Indications for investigation included assessment of causes of digestive symptoms or maldigestion. Patients had laboratory and other imaging or endoscopic investigations that showed no evidence of organic pathology. This retrospective cohort study reports the performance of a combined 20g lactulose H2 breath test with radiographic abdominal imaging to assess OCTT, SIBO, and carbohydrate tolerance. The novel innovation in this method is to confirm OCTT by taking an X-ray of the abdomen when H2 production increases during the examination. If contrast agent is NOT visible in the caecum when H2 increases, then SIBO is present. Otherwise, if contrast agent is present in the caecum, then results confirm OCTT and carbohydrate intolerance.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients referred for breath testing to assess the causes of digestive symptoms or maldigestion 2020-2024

You may qualify if:

• Patients referred for breath testing to assess the causes of digestive symptoms or maldigestion 2020-2024
• Patients signed general consent to allow use of clinical data obtained during clinical assessment and breath testing to be used in research project.

Sponsors & Collaborators

• Klinik Arlesheim: lead
• Kantonsspital Baselland Bruderholz: collaborator

Study Sites (1)

Klinik Arlesheim

Arlesheim, Basel-Landschaft, 4144, Switzerland

RECRUITING

MeSH Terms

Conditions

Irritable Bowel Syndrome

Condition Hierarchy (Ancestors)

Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases

Central Study Contacts

Mark R Fox, MD

CONTACT

+41791934795; dr.mark.fox@gmail.com

Raik Hartwig, Dipl. med.

CONTACT

raik.hartwig@klinik-arlesheim.ch

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 11, 2025
• First Posted: August 28, 2025
• Study Start: August 1, 2025
• Primary Completion: December 31, 2025
• Study Completion (Estimated): December 31, 2026
• Last Updated: August 28, 2025

Record last verified: 2025-08

Locations

CH (1)