Adhesive Small Bowel ObstructionPhase 4COMBONCT07084441
Comparison of Outcomes of Management of Bowel Obstruction
A Phase 4 study testing Dexamethasone and Supportive Care in people with Adhesive Small Bowel Obstruction, run by University of Washington at 4 sites in United States.
Trial summary
The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) trial is a patient-level randomized trial of a short course of dexamethasone + supportive care vs supportive care alone for patients with adhesion-related small bowel obstruction (aSBO). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Adhesive Small Bowel Obstruction
- What is being tested?
- Dexamethasone and Supportive Care
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 550 participants
- Where
- 4 sitesUnited States
- Study dates
- 3 Feb 2026to Dec 2030
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults ≥18 years of age recruited from UWMC
- Patients presenting to surgical services through the Emergency Department, diagnosis of SBO, consulted by surgeon, and an urgent or emergency operation is deemed not necessary by surgeon.
- Diagnosis of aSBO is established by;
- CT findings consistent with diagnosis of SBO; and
- signs and symptoms consistent with SBO; and
- Adhesions from prior abdominopelvic surgery are the likely cause of SBO (absence of incarcerated hernia, internal hernia, masses, fistula, stricture, volvulus, acute episode of inflammatory bowel disease (IBD) flare, etc.).
- Ability to provide written or electronic informed consent in English and answer teach-back questions
Who cannot join
- Signs and symptoms of peritonitis with emergency operation planned
- Planned urgent operation within the next 12 hours
- Allergy to dexamethasone
- Surgery within prior 6 weeks
- Unable or unwilling to return or be contacted for and/or complete research surveys
- Currently incarcerated in a detention facility or in police custody (patients wearing a monitoring device can be enrolled) at baseline/screening
- Individuals with latent infections who have an increased risk of infection.
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States4 sites, 4 recruiting
- Recruiting
Columbia University Medical Center
New York, New York, 10032
- Recruiting
Harborview Medical Center
Seattle, Washington, 98104
- Recruiting
UW Medical Center - Northwest
Seattle, Washington, 98133
- Recruiting
University of Washington Medical Center Montlake
Seattle, Washington, 98195
About this study
The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) trial is a patient-level randomized trial of a short course of dexamethasone + supportive care vs supportive care alone for patients with adhesion-related small bowel obstruction (aSBO). The goal of the COMBO trial is to answer the question: Can Dexamethasone increases the proportion of patients with resolution of aSBO with non-operative management (without complication) based on an established minimal important clinical difference.
Read the detailed description
Millions of Americans each year experience adhesion-related small bowel obstruction (aSBO), a condition associated with significant morbidity and prolonged hospitalization. Adhesions formed after previous abdominopelvic surgery can cause twisting of the bowel resulting in injury and a cascade of inflammation that results in progressive bowel wall edema with narrowing of the bowel lumen. This leads to or worsens the bowel obstruction. Reversing this inflammation has the potential to reduce the severity and impact of aSBO, hasten the return of bowel function and avoid an emergency operation to treat the obstruction. Dexamethasone, administered intravenously 2-3 times/day for 5-7 days, has been found effective in patients with a form of SBO related to malignancy (malignant ascites or metastatic disease). A Cochrane review evaluated three RCTs of dexamethasone in patients with malignant SBO and found "evidence that dexamethasone…may bring about the resolution of bowel obstruction" and avoid the need for surgical interventionxx . An underappreciated aspect of these RCTs is that almost all patients had a history of abdominopelvic surgery. Since it is difficult to distinguish the extent to which an SBO is caused by adhesions from prior surgery or mass effect related to malignant ascites or metastases, we hypothesize that dexamethasone may be efficacious in resolving aSBO as well.
The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) study is a double-blinded randomized study of a short course of dexamethasone and supportive care vs. supportive care alone for patients with aSBO. The primary outcome is resolution of SBO without operative management and/or major complications as defined using modified National Surgical Quality Improvement Program (NSQIP) criteria. Differences in secondary outcomes-clinical, healthcare utilization and patient-reported outcomes will be explored overall and across subgroups (e.g., based on severity of aSBO, history of aSBO, sex). Reducing inflammation with dexamethasone- a readily available and safe intervention - may improve the likelihood of non-operative management of aSBO and could change the management of millions of patients with this condition.
- Conditions
- Adhesive Small Bowel Obstruction
- Being tested
- Dexamethasone, Supportive Care
- Keywords
- asbo, sbo, small bowel obstruction, dexamethasone
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DexamethasoneDrug
*Please see description for dexamethasone + supportive care arm.
Supportive CareOther
*Please see description for supportive care arm.
| Study group | Role | What they receive |
|---|---|---|
| Dexamethasone | Active comparator | Supportive care and dexamethasone 8 mg administered intravenously (using blinded packaging) once daily for up to 5 days until SBO is resolved or patient becomes surgical candidate. Receives: Drug: Dexamethasone; Other: Supportive Care |
| Supportive Care | Placebo comparator | Supportive care in both arms could include nasogastric tube (NGT) decompression, IV hydration, and serial abdominal exams as part of the standard of care for bowel obstruction management. Receives: Other: Supportive Care |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resolution of adhesive Small Bowel Obstruction (aSBO)
The primary outcome is the resolution of aSBO, defined as the absence of obstruction symptoms, in patients receiving dexamethasone + supportive care compared to those receiving supportive care alone
Measured: 30 days
Secondary outcomes (3)
Hospital readmissions - 1 Year
The outcome for this aim is the comparison of healthcare utilization (e.g., readmissions) between the dexamethasone and supportive care groups
Measured: 1 Year
Patient-Reported Outcomes (PROs) - Gastrointestinal Quality of Life Index (GIQLI)
A 36-item questionnaire assessing 5 domains: GI symptoms, physical function, emotional well-being, social well-being, and perception of medical treatment measured by a single item question. Each item has 5 response choices (i.e., all of the time, most of the time, some of the time, a little of the time, never). In addition, the measure produces an overall quality of life score (0-144) where higher numbers indicate greater QoL.
The outcome will be the comparison of GIQLI score between the dexamethasone and supportive care groups.
Measured: 30 days
Hospital readmissions - 30 day
The outcome for this aim is the comparison of healthcare utilization (e.g., readmissions) between the dexamethasone and supportive care groups
Measured: 30 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2025
- Study start3 Feb 2026
- Primary completionJun 2030 (estimated)
- Study completionDec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Adhesive Small Bowel ObstructionStudies of the same condition, open and under way.
- More trials run by University of WashingtonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 550 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Washington
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Flum, University of Washington
- Investigators
- David Flum, MD MPH, Principal investigator, University of Washington
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07084441
- Sponsor's protocol ID
- STUDY00020975
- Acronym
- COMBO
- Status last verified
- May 2026
- First submitted
- 16 Jul 2025
- Last updated
- 7 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Outcomes of Management of Bowel Obstruction
- ClinicalTrials.gov ID
- NCT07084441
- Acronym / sponsor ID
- COMBO / STUDY00020975
- Conditions
- Adhesive Small Bowel Obstruction
- Keywords
- asbo, sbo, small bowel obstruction, dexamethasone
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 550 participants (estimated)
- Lead sponsor
- University of WashingtonUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 3 Feb 2026 (actual)
- Primary completion
- Jun 2030 (estimated)
- Study completion
- Dec 2030 (estimated)
- First posted
- 24 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) trial is a patient-level randomized trial of a short course of dexamethasone + supportive care vs supportive care alone for patients with adhesion-related small bowel obstruction (aSBO). The goal of the COMBO trial is to answer the question: Can Dexamethasone increases the proportion of patients with resolution of aSBO with non-operative management (without complication) based on an established minimal important clinical difference.
Detailed description
Millions of Americans each year experience adhesion-related small bowel obstruction (aSBO), a condition associated with significant morbidity and prolonged hospitalization. Adhesions formed after previous abdominopelvic surgery can cause twisting of the bowel resulting in injury and a cascade of inflammation that results in progressive bowel wall edema with narrowing of the bowel lumen. This leads to or worsens the bowel obstruction. Reversing this inflammation has the potential to reduce the severity and impact of aSBO, hasten the return of bowel function and avoid an emergency operation to treat the obstruction. Dexamethasone, administered intravenously 2-3 times/day for 5-7 days, has been found effective in patients with a form of SBO related to malignancy (malignant ascites or metastatic disease). A Cochrane review evaluated three RCTs of dexamethasone in patients with malignant SBO and found "evidence that dexamethasone…may bring about the resolution of bowel obstruction" and avoid the need for surgical interventionxx . An underappreciated aspect of these RCTs is that almost all patients had a history of abdominopelvic surgery. Since it is difficult to distinguish the extent to which an SBO is caused by adhesions from prior surgery or mass effect related to malignant ascites or metastases, we hypothesize that dexamethasone may be efficacious in resolving aSBO as well.
The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) study is a double-blinded randomized study of a short course of dexamethasone and supportive care vs. supportive care alone for patients with aSBO. The primary outcome is resolution of SBO without operative management and/or major complications as defined using modified National Surgical Quality Improvement Program (NSQIP) criteria. Differences in secondary outcomes-clinical, healthcare utilization and patient-reported outcomes will be explored overall and across subgroups (e.g., based on severity of aSBO, history of aSBO, sex). Reducing inflammation with dexamethasone- a readily available and safe intervention - may improve the likelihood of non-operative management of aSBO and could change the management of millions of patients with this condition.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Dexamethasone | Active comparator | Drug: Dexamethasone, Other: Supportive CareSupportive care and dexamethasone 8 mg administered intravenously (using blinded packaging) once daily for up to 5 days until SBO is resolved or patient becomes surgical candidate. |
| Supportive Care | Placebo comparator | Other: Supportive CareSupportive care in both arms could include nasogastric tube (NGT) decompression, IV hydration, and serial abdominal exams as part of the standard of care for bowel obstruction management. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adults ≥18 years of age recruited from UWMC
- Patients presenting to surgical services through the Emergency Department, diagnosis of SBO, consulted by surgeon, and an urgent or emergency operation is deemed not necessary by surgeon.
- Diagnosis of aSBO is established by;
- Ability to provide written or electronic informed consent in English and answer teach-back questions
Key exclusion criteria (7 listed)
- Signs and symptoms of peritonitis with emergency operation planned
- Planned urgent operation within the next 12 hours
- Allergy to dexamethasone
- Surgery within prior 6 weeks
- Unable or unwilling to return or be contacted for and/or complete research surveys
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dexamethasone*Please see description for dexamethasone + supportive care arm. | Drug | Dexamethasone |
| Supportive Care*Please see description for supportive care arm. | Other | Dexamethasone, Supportive Care |
Primary outcome
Resolution of adhesive Small Bowel Obstruction (aSBO)
Time frame: 30 days
The primary outcome is the resolution of aSBO, defined as the absence of obstruction symptoms, in patients receiving dexamethasone + supportive care compared to those receiving supportive care alone
3 secondary outcomes
Hospital readmissions - 1 Year
Time frame: 1 Year
Patient-Reported Outcomes (PROs) - Gastrointestinal Quality of Life Index (GIQLI)
Time frame: 30 days
Hospital readmissions - 30 day
Time frame: 30 day
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 May 2026.
- Individual participant dataSharing planned: No
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Water-Soluble Contrast Induced Intestinal Stimulation for the Treatment of Small Bowel Obstruction: A Feasibility Study
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Adhesion Prevention in ASBO Surgery Using 4DryField® PH
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David Flum, MD MPH principal investigator
University of Washington
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Dexamethasone and Supportive Care in people with Adhesive Small Bowel Obstruction, run by University of Washington at 4 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kelsey Pullar, MPH (206.221.8247, kpullar@uw.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Resolution of adhesive Small Bowel Obstruction (aSBO) (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 May 2026.