Elective Colon SurgeryPhase 4REaCT-NSQIPNCT03663504
Comparing No Mechanical Bowel Preparation With Oral Antibiotics Alone in Patients Undergoing Elective Colon Surgery
A Phase 4 study testing No Preparation and Neomycin and Flagyl in people with Elective Colon Surgery, run by Ottawa Hospital Research Institute at 6 sites in Canada.
Trial summary
The REaCT NSQIP will compare oral antibiotics vs. no antibiotics, which are two standards of care treatments for preoperative preparation of the bowel prior to colorectal surgery Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Elective Colon Surgery
- What is being tested?
- No Preparation and Neomycin and Flagyl
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 630 participants
- Where
- 6 sitesCanada
- Study dates
- 23 Oct 2018to Oct 2026
- 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
- Patients undergoing elective, non-emergency colon, resection surgery or abdominal perineal resection and no other requirements exists for a mechanical bowel preparation (as determined by the operating surgeon)
- 18 years of age or older
- Able to provide oral consent
Who cannot join
- Contraindication to the oral antibiotics, including allergies or adverse reactions to either metronidazole or neomycin
- Undergoing a rectal resection with a planned anastomosis (these patients will all receive MBP)
- Emergency surgery where no opportunity to administer preoperative oral antibiotics exists
- Requirement for a MBP (i.e. rectal resection with pelvic anastomosis, intraoperative colonoscopy, or at the discretion of the treating surgeon
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
Canada6 sites
The Queen Elizabeth II Health Sciences Centre
Halifax, Nova Scotia, B3H 3A7
The Ottawa Hospital Cancer Centre
Ottawa, Ontario, K1H 8M2
Hôpital Montfort
Ottawa, Ontario, K1K 0T2
Queensway Carleton Hospital
Ottawa, Ontario, K2H 8P4
Renfrew Victoria Hospital
Renfrew, Ontario, K7V 1P6
University Health Network
Toronto, Ontario, M5G 2C4
About this study
Official title: A Randomised Study Comparing No Mechanical Bowel Preparation With Oral Antibiotics Alone in Patients Undergoing Elective Colon Surgery (REaCT-NSQIP)
The REaCT NSQIP will compare oral antibiotics vs. no antibiotics, which are two standards of care treatments for preoperative preparation of the bowel prior to colorectal surgery
Read the detailed description
The divergence of clinical practice guidelines, in addition to observation from the large North American retrospective studies, suggest that surgeons and centers have not established a standard of care for the preoperative preparation of the bowel prior to colorectal surgery. Specifically, some centers are employing no preparation, others are administering a mechanical bowel preparation (MBP) and oral antibiotics and still others are using oral antibiotics alone. Recently, the Canadian Society of Colorectal Surgeons was unable to come to a consensus when attempting to update their preoperative guidelines because of the lack of agreement on best practice (personal communication). This is an important yet controversial topic in colorectal surgery and a clinical trial comparing two standard of care therapies will impact current practice in Canada. The REaCT-NSQIP study compares post-operative surgical infectious complications, length of stay, incidence of C. difficile rates, patient quality of life and cost-effectiveness in patients undergoing elective colorectal surgery with either no preparation or oral antibiotics. Data will be collected from the National Surgical Quality Improvement Program (NSQIP) and from patient quality of life questionnaires preoperatively and 30 days postoperatively
In this study, it is hypothesized that it is the oral antibiotics, and not the MBP, that is responsible for the reduction in postoperative infectious surgical complications (deep or superficial surgical site infection (SSI)) in patients undergoing elective colorectal resections. This improvement in postoperative infectious complications is not anticipated to result in a clinically significant increase in postoperative C. difficile infections or antibiotic resistant hospital-acquired infections.
- Conditions
- Elective Colon Surgery
- Being tested
- No Preparation, Neomycin and Flagyl
- Keywords
- Oral Antibiotics, Preoperative Mechanical Bowel Preparation, Surgical Site Infection, C. difficile
- Medical subject headings
- Surgical Wound Infection
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No PreparationOther
No preparation before surgery
Neomycin and FlagylDrug
Also called Metronidazole
Oral antibiotic (Neomycin and Flagyl) taken the day before the surgery
| Study group | Role | What they receive |
|---|---|---|
| No Preparation | Active comparator | No preparation before surgery Receives: Other: No Preparation |
| Oral Antibiotics | Active comparator | Oral antibiotics (neomycin and flagyl), to be taken the day before the surgery Receives: Drug: Neomycin and Flagyl |
What is being measured
The primary outcome is the main question the study is designed to answer.
Post-Operative Surgical Infection Complication
To evaluate that use of oral antibiotics (neomycin and flagyl), administered the day prior to elective colonic resection is associated with a significant reduction in postoperative (within 30 days) surgical infectious complications (superficial and deep space infections).
Measured: 30 days
Secondary outcomes (9)
Grade III-IV Postoperative Surgical Site Infectious Complication
To evaluate the effects of oral antibiotics on Grade III-IV (Clavien-Dindo classification) postoperative surgical site infectious complication (at 30 days).
Measured: 30 days
Postoperative Infections Complications
To evaluate the effects of oral antibiotics on postoperative infections complications classified as deep SSI, superficial SSI or non-SSI infectious complications (i.e. urinary tract infection, pneumonia, at 30 days).
Measured: 30 days
Overall Postoperative Complication Rate
To evaluate the effects of oral antibiotics on overall postoperative complication rate (at 30 days).
Measured: 30 days
Postoperative Length of Stay
To evaluate the effects of oral antibiotics on postoperative length of stay (LOS).
Measured: Number of days spent in hospital post-operatively, average of 6 days
Incidence of Postoperative C. difficile Infections
To evaluate the effects of oral antibiotics on the incidence of postoperative C. difficile infections (at 90 days).
Measured: 90 days
Incidence of Antibiotics Resistant Postoperative Infectious Complications
To evaluate the effects of oral antibiotics on the incidence of of antibiotics resistant postoperative infectious complications (at 30 days)
Measured: 30 days
Patient Quality of Life
To evaluate the effects of oral antibiotics on patient quality of life by administering the SF-36 questionnaire, undertaken preoperatively and at 30 days postoperatively. The Short Form-36 (SF-36) is a 36-item, patient reported survey that is a measure of health status and commonly used in health economics. This SF-36 consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. A low score denounces a worse outcome compared to a higher score that denounces a better outcome. The eight sections are: vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social role functioning and mental health.
Measured: 30 days
Direct Estimation of Health Utility Values
To evaluate the effects of oral antibiotics on patient quality of life by administering the EQ-5D-5L questionnaire, undertaken preoperatively and 30 days postoperatively. The EuroQol 5 Dimension 5 Level (EQ-5D-5L) questionnaire consists of two sections; the EQ-5D-5L descriptive system and the EQ Visual Analogue scale. The descriptive system comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression). There are 5 levels associated with it; no problems, slight problems, moderate problems, severe problems and extreme problems. The scale range of 1-5 is used for the 5 dimensions in the descriptive system where 1 is the best outcome and 5 is the worst outcome. The Visual Analogue scale records the respondent's self-rated health on a vertical, visual scale with endpoints labelled 'the best health you can imagine' at the top and 'the worst health you can imagine' at the bottom. This ranges 0 being the worst outcome to 100 being the best outcome.
Measured: 30 days
Incremental Cost-Effectiveness Ratio
To evaluate the effects of antibiotics on the incremental cost-effectiveness ratio
Measured: Through to study completion, an average of 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2018
- Study start23 Oct 2018
- Primary completionAug 2026 (estimated)
- Study completionOct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Elective Colon SurgeryStudies of the same condition, open and under way.
- More trials run by Ottawa Hospital Research InstituteThe 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
- None (open label)
- Enrolment
- 630 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ottawa Hospital Research Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Rebecca Auer, MD, Principal investigator, Ottawa Hospital Research InstituteSameer Apte, MD, Principal investigator, The Ottawa Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03663504
- Sponsor's protocol ID
- OTT 18-03
- Other IDs
- REaCT-NSQIP
- Acronym
- REaCT-NSQIP
- Status last verified
- Jun 2026
- First submitted
- 7 Aug 2018
- Last updated
- 16 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Apte SS, Moloo H, Jeong A, Liu M, Vandemeer L, Suh K, Thavorn K, Fergusson DA, Clemons M, Auer RC. Prospective randomised controlled trial using the REthinking Clinical Trials (REaCT) platform and National Surgical Quality Improvement Program (NSQIP) to compare no preparation versus preoperative oral antibiotics alone for surgical site infection rates in elective colon surgery: a protocol. BMJ Open. 2020 Jul 9;10(7):e036866. doi: 10.1136/bmjopen-2020-036866.
PubMed 32647023Willis MA, Toews I, Soltau SL, Kalff JC, Meerpohl JJ, Vilz TO. Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery. Cochrane Database Syst Rev. 2023 Feb 7;2(2):CD014909. doi: 10.1002/14651858.CD014909.pub2.
PubMed 36748942
Study at a glance
From the registry record, last updated by the sponsor on 16 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomised Study Comparing No Mechanical Bowel Preparation With Oral Antibiotics Alone in Patients Undergoing Elective Colon Surgery (REaCT-NSQIP)
- ClinicalTrials.gov ID
- NCT03663504
- Acronym / sponsor ID
- REaCT-NSQIP / OTT 18-03
- Conditions
- Elective Colon Surgery
- Keywords
- Oral Antibiotics, Preoperative Mechanical Bowel Preparation, Surgical Site Infection, C. difficile
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 630 participants (actual)
- Lead sponsor
- Ottawa Hospital Research InstituteUniversity, hospital or other
- Study start
- 23 Oct 2018 (actual)
- Primary completion
- Aug 2026 (estimated)
- Study completion
- Oct 2026 (estimated)
- First posted
- 10 Sep 2018 (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 REaCT NSQIP will compare oral antibiotics vs. no antibiotics, which are two standards of care treatments for preoperative preparation of the bowel prior to colorectal surgery
Detailed description
The divergence of clinical practice guidelines, in addition to observation from the large North American retrospective studies, suggest that surgeons and centers have not established a standard of care for the preoperative preparation of the bowel prior to colorectal surgery. Specifically, some centers are employing no preparation, others are administering a mechanical bowel preparation (MBP) and oral antibiotics and still others are using oral antibiotics alone. Recently, the Canadian Society of Colorectal Surgeons was unable to come to a consensus when attempting to update their preoperative guidelines because of the lack of agreement on best practice (personal communication). This is an important yet controversial topic in colorectal surgery and a clinical trial comparing two standard of care therapies will impact current practice in Canada. The REaCT-NSQIP study compares post-operative surgical infectious complications, length of stay, incidence of C. difficile rates, patient quality of life and cost-effectiveness in patients undergoing elective colorectal surgery with either no preparation or oral antibiotics. Data will be collected from the National Surgical Quality Improvement Program (NSQIP) and from patient quality of life questionnaires preoperatively and 30 days postoperatively
In this study, it is hypothesized that it is the oral antibiotics, and not the MBP, that is responsible for the reduction in postoperative infectious surgical complications (deep or superficial surgical site infection (SSI)) in patients undergoing elective colorectal resections. This improvement in postoperative infectious complications is not anticipated to result in a clinically significant increase in postoperative C. difficile infections or antibiotic resistant hospital-acquired infections.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| No Preparation | Active comparator | Other: No PreparationNo preparation before surgery |
| Oral Antibiotics | Active comparator | Drug: Neomycin and FlagylOral antibiotics (neomycin and flagyl), to be taken the day before the surgery |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients undergoing elective, non-emergency colon, resection surgery or abdominal perineal resection and no other requirements exists for a mechanical bowel preparation (as determined by the operating surgeon)
- 18 years of age or older
- Able to provide oral consent
Key exclusion criteria (4 listed)
- Contraindication to the oral antibiotics, including allergies or adverse reactions to either metronidazole or neomycin
- Undergoing a rectal resection with a planned anastomosis (these patients will all receive MBP)
- Emergency surgery where no opportunity to administer preoperative oral antibiotics exists
- Requirement for a MBP (i.e. rectal resection with pelvic anastomosis, intraoperative colonoscopy, or at the discretion of the treating surgeon
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 |
|---|---|---|
| No PreparationNo preparation before surgery | Other | No Preparation |
| Neomycin and FlagylAlso: MetronidazoleOral antibiotic (Neomycin and Flagyl) taken the day before the surgery | Drug | Oral Antibiotics |
Primary outcome
Post-Operative Surgical Infection Complication
Time frame: 30 days
To evaluate that use of oral antibiotics (neomycin and flagyl), administered the day prior to elective colonic resection is associated with a significant reduction in postoperative (within 30 days) surgical infectious complications (superficial and deep space infections).
9 secondary outcomes
Grade III-IV Postoperative Surgical Site Infectious Complication
Time frame: 30 days
Postoperative Infections Complications
Time frame: 30 days
Overall Postoperative Complication Rate
Time frame: 30 days
Postoperative Length of Stay
Time frame: Number of days spent in hospital post-operatively, average of 6 days
Incidence of Postoperative C. difficile Infections
Time frame: 90 days
Incidence of Antibiotics Resistant Postoperative Infectious Complications
Time frame: 30 days
Patient Quality of Life
Time frame: 30 days
Direct Estimation of Health Utility Values
Time frame: 30 days
Incremental Cost-Effectiveness Ratio
Time frame: Through to study completion, an average of 2 years
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 16 Jun 2026.
- Background: PubMed 32647023Apte SS, Moloo H, Jeong A, Liu M, Vandemeer L, Suh K, Thavorn K, Fergusson DA, Clemons M, Auer RC. Prospective randomised controlled trial using the REthinking Clinical Trials (REaCT) platform and National Surgical Quality Improvement Program (NSQIP) to compare no preparation versus preoperative oral antibiotics alone for surgical site infection rates in elective colon surgery: a protocol. BMJ Open. 2020 Jul 9;10(7):e036866. doi: 10.1136/bmjopen-2020-036866.
- Derived from this study: PubMed 36748942Willis MA, Toews I, Soltau SL, Kalff JC, Meerpohl JJ, Vilz TO. Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery. Cochrane Database Syst Rev. 2023 Feb 7;2(2):CD014909. doi: 10.1002/14651858.CD014909.pub2.
- The Rethinking Clinical Trials (REaCT) websiteLink provided by the sponsor.
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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. This study is not recruiting at the moment.
Rebecca Auer, MD principal investigator
Ottawa Hospital Research Institute
Sameer Apte, MD principal investigator
The Ottawa Hospital
6 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 No Preparation and Neomycin and Flagyl in people with Elective Colon Surgery, run by Ottawa Hospital Research Institute at 6 sites in Canada.
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 3 inclusion and 4 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: under way, not looking for participants, as of the sponsor's last update on 16 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in Canada. 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. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Post-Operative Surgical Infection Complication (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03663504, which also lists 2 linked publications.
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 16 Jun 2026.