Postoperative IleusNCT04547868
Can Coffee/Caffeine Improve Post-Operative Gastrointestinal Recovery
A study testing Coffee, Decaffeinated Coffee and Warm water in people with Postoperative Ileus and Caffeine, run by Sunnybrook Health Sciences Centre at 3 sites in Canada.
Trial summary
Disruption of the normal gastrointestinal (GI) motility is a well-known consequence of major surgery. The pathophysiology behind this phenomenon is not fully understood but involves the autonomic nervous system as well as a systemic stress response to surgery. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Postoperative Ileus, Caffeine
- What is being tested?
- Coffee, Decaffeinated Coffee and Warm water
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 174 participants
- Where
- 3 sitesCanada
- Study dates
- 5 Oct 2021to 21 Aug 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
- Age ≥ 18 years
- Planned elective laparoscopic or open abdominal surgery
- Patient is scheduled to remain in hospital for at least one night, post-operatively
Who cannot join
- Known intolerance to coffee or caffeine
- Unwilling to stop current caffeine consumption (coffee or tea) during trial
Trial locations and contacts
3 sites in 1 country.
Canada3 sites
North York General Hospital
North York, Ontario, M2K 1E1
The Ottawa Hospital
Ottawa, Ontario, K1H 8L6
Sunnybrook Health Sciences Centre
Toronto, Ontario, M4N 3M5
About this study
Official title: Can Coffee/Caffeine Improve Post-Operative Gastrointestinal Recovery? A Vanguard Randomized Controlled Trial
Disruption of the normal gastrointestinal (GI) motility is a well-known consequence of major surgery. The pathophysiology behind this phenomenon is not fully understood but involves the autonomic nervous system as well as a systemic stress response to surgery. A number of factors interfere with GI motor activity, such as the direct manipulation of intestines during surgery and the use of opioid analgesia. Post-operative ileus (POI) refers to a delay in regaining GI motility beyond the anticipated normal duration of time. Signs and symptoms include nausea, vomiting, abdominal distention, the absence of flatus or stool in the preceding 24 hours, and/or an inability to tolerate oral intake. The incidence of POI in abdominal surgery is estimated to be approximately 10%-30%. Beyond increased patient discomfort and distress, the development of POI is associated with increased healthcare costs.
Coffee is a popular beverage: two thirds of Canadians are coffee drinkers, averaging approximately 3.2 cups per day. Coffee is composed of hundreds of chemicals, many with demonstrated pharmacologic effects. The most well-known of these compounds is caffeine, known to exert a stimulatory effect on the cardiovascular and nervous system. A recent systematic review of 7 randomized controlled trials (N=606 colorectal and gynecology surgical patients) determined that the consumption of coffee reduced the time of several measures of GI recovery, such as time to tolerance of food, without any increased rate of complications or adverse events although overall, the evidence was graded as low to moderate certainty, and further confirmatory studies are needed. In this trial, patients aged 18 years or higher who undergo laparoscopic or open abdominal surgery, with an estimated length of stay > 24 hours will be randomized to receive approximately one cup of either coffee, decaffeinated coffee, or warm water, three times daily. This trial will be conducted under the IMPACTS (Innovative, Multicentre, Patient-centred Approach to Clinical Trials in Surgery) program umbrella and will follow IMPACTS methodology. For the Vanguard trial, the aim is to determine the feasibility of conducting a definitive trial. Future outcomes of interest include: time to first flatus, time to first bowel movement, placement of an NG tube, length of stay in hospital, 30-day mortality, and 30-day postoperative complications.
Read the detailed description
Background/rationale: The development of POI is a common complication of surgery that is detrimental to patient well-being and ultimately leads to significant healthcare costs. Coffee is a popular drink among Canadians and appears to exert a positive effect on GI motility. This beverage may provide an inexpensive, easily administered and well-tolerated intervention to accelerate post-operative GI recovery, and thus reduce POI. The current literature, while promising, is insufficient and merits further investigation in the form of a high-quality randomized controlled trial.
Objectives: Before embarking on a definitive RCT, this pilot trial has five specific feasibility objectives:
- To assess our ability to accrue patients using the IMPACTS Program platform, at multiple institutions, over the course of one year.
- To assess our ability to adaptively randomize patients and deliver the randomized assignment using the IMPACTS Program platform, over the course of one year.
- To assess our ability to collect complete data directly from participants (patients and clinicians) on time to first flatus and time to first bowel movement over the course of one year.
- To examine our ability to carry out data linkages using the IMPACTS Program platform over the course of one year.
- To estimate the change in time to first flatus to inform the sample size calculation for the definitive trial.
Study design: This is a multicentre, pragmatic, 3-arm parallel group Vanguard feasibility randomized controlled trial. Patients will be randomly assigned to consume coffee, decaffeinated coffee, or warm water. If feasibility is demonstrated during the pilot trial, we will plan to conduct a definitive trial. If there are only minimal changes to the protocol, we will include data from the pilot phase into the definitive trial analysis (i.e. a Vanguard design).
- Conditions
- Postoperative Ileus, Caffeine
- Being tested
- Coffee, Decaffeinated Coffee, Warm water
- Keywords
- Postoperative gastrointestinal recovery, Gastrointestinal motility, Coffee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CoffeeOther
Once the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of coffee will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices.
Decaffeinated CoffeeOther
Once the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of decaffeinated coffee will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices.
Warm waterOther
Once the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of warm water will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices.
| Study group | Role | What they receive |
|---|---|---|
| Coffee | Experimental | Caffeinated coffee beverage Receives: Other: Coffee |
| Decaffeinated coffee | Active comparator | Decaffeinated coffee beverage Receives: Other: Decaffeinated Coffee |
| Warm water | Placebo comparator | Warm water beverage Receives: Other: Warm water |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessment of accrual
Average number of patients enrolled per month across the 3 sites for the trial: feasible if 10 or more
Measured: 1 year
Ability to deliver intervention patient is randomized to receive
Feasible if > 90% of patients receive the correct intervention
Measured: 1 year
Ability to collect complete data for patient-reported outcomes
Feasible if > 80% of data is collected
Measured: 1 year
Ability to link data from patient-reported outcome measures with Institute for Clinical/Evaluative Sciences and National Surgical Quality Improvement Program datasets
Feasible if linkage is possible in > 90% of patients
Measured: 1 year
Measurement of baseline data
- Median number of hours until flatus in control group
- Median number of hours until flatus in coffee and decaffeinated coffee groups
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Sep 2020
- Study start5 Oct 2021
- Primary completion30 Jul 2022
- Study completion21 Aug 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative IleusStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Pragmatic, multicentre, open-label, three-arm parallel group Vanguard feasibility randomized controlled trial
- Masking
- None (open label)
- Enrolment
- 174 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sunnybrook Health Sciences Centre
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Paul Karanicolas, Sunnybrook Health Sciences Centre
- Investigators
- Paul Karanicolas, MD PhD, Principal investigator, Sunnybrook Health Sciences Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04547868
- Sponsor's protocol ID
- CTO Project ID: 2121
- Status last verified
- Jan 2026
- First submitted
- 8 Sep 2020
- Last updated
- 12 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Can Coffee/Caffeine Improve Post-Operative Gastrointestinal Recovery? A Vanguard Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT04547868
- Acronym / sponsor ID
- CTO Project ID: 2121
- Conditions
- Postoperative Ileus, Caffeine
- Keywords
- Postoperative gastrointestinal recovery, Gastrointestinal motility, Coffee
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 174 participants (actual)
- Lead sponsor
- Sunnybrook Health Sciences CentreUniversity, hospital or other
- Study start
- 5 Oct 2021 (actual)
- Primary completion
- 30 Jul 2022 (actual)
- Study completion
- 21 Aug 2022 (actual)
- First posted
- 14 Sep 2020 (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.
Disruption of the normal gastrointestinal (GI) motility is a well-known consequence of major surgery. The pathophysiology behind this phenomenon is not fully understood but involves the autonomic nervous system as well as a systemic stress response to surgery. A number of factors interfere with GI motor activity, such as the direct manipulation of intestines during surgery and the use of opioid analgesia. Post-operative ileus (POI) refers to a delay in regaining GI motility beyond the anticipated normal duration of time. Signs and symptoms include nausea, vomiting, abdominal distention, the absence of flatus or stool in the preceding 24 hours, and/or an inability to tolerate oral intake. The incidence of POI in abdominal surgery is estimated to be approximately 10%-30%. Beyond increased patient discomfort and distress, the development of POI is associated with increased healthcare costs.
Coffee is a popular beverage: two thirds of Canadians are coffee drinkers, averaging approximately 3.2 cups per day. Coffee is composed of hundreds of chemicals, many with demonstrated pharmacologic effects. The most well-known of these compounds is caffeine, known to exert a stimulatory effect on the cardiovascular and nervous system. A recent systematic review of 7 randomized controlled trials (N=606 colorectal and gynecology surgical patients) determined that the consumption of coffee reduced the time of several measures of GI recovery, such as time to tolerance of food, without any increased rate of complications or adverse events although overall, the evidence was graded as low to moderate certainty, and further confirmatory studies are needed. In this trial, patients aged 18 years or higher who undergo laparoscopic or open abdominal surgery, with an estimated length of stay > 24 hours will be randomized to receive approximately one cup of either coffee, decaffeinated coffee, or warm water, three times daily. This trial will be conducted under the IMPACTS (Innovative, Multicentre, Patient-centred Approach to Clinical Trials in Surgery) program umbrella and will follow IMPACTS methodology. For the Vanguard trial, the aim is to determine the feasibility of conducting a definitive trial. Future outcomes of interest include: time to first flatus, time to first bowel movement, placement of an NG tube, length of stay in hospital, 30-day mortality, and 30-day postoperative complications.
Detailed description
Background/rationale: The development of POI is a common complication of surgery that is detrimental to patient well-being and ultimately leads to significant healthcare costs. Coffee is a popular drink among Canadians and appears to exert a positive effect on GI motility. This beverage may provide an inexpensive, easily administered and well-tolerated intervention to accelerate post-operative GI recovery, and thus reduce POI. The current literature, while promising, is insufficient and merits further investigation in the form of a high-quality randomized controlled trial.
Objectives: Before embarking on a definitive RCT, this pilot trial has five specific feasibility objectives:
- To assess our ability to accrue patients using the IMPACTS Program platform, at multiple institutions, over the course of one year.
- To assess our ability to adaptively randomize patients and deliver the randomized assignment using the IMPACTS Program platform, over the course of one year.
- To assess our ability to collect complete data directly from participants (patients and clinicians) on time to first flatus and time to first bowel movement over the course of one year.
- To examine our ability to carry out data linkages using the IMPACTS Program platform over the course of one year.
- To estimate the change in time to first flatus to inform the sample size calculation for the definitive trial.
Study design: This is a multicentre, pragmatic, 3-arm parallel group Vanguard feasibility randomized controlled trial. Patients will be randomly assigned to consume coffee, decaffeinated coffee, or warm water. If feasibility is demonstrated during the pilot trial, we will plan to conduct a definitive trial. If there are only minimal changes to the protocol, we will include data from the pilot phase into the definitive trial analysis (i.e. a Vanguard design).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Pragmatic, multicentre, open-label, three-arm parallel group Vanguard feasibility randomized controlled trial
| Arm | Type | Receives |
|---|---|---|
| Coffee | Experimental | Other: CoffeeCaffeinated coffee beverage |
| Decaffeinated coffee | Active comparator | Other: Decaffeinated CoffeeDecaffeinated coffee beverage |
| Warm water | Placebo comparator | Other: Warm waterWarm water beverage |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age ≥ 18 years
- Planned elective laparoscopic or open abdominal surgery
- Patient is scheduled to remain in hospital for at least one night, post-operatively
Key exclusion criteria (2 listed)
- Known intolerance to coffee or caffeine
- Unwilling to stop current caffeine consumption (coffee or tea) during trial
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 |
|---|---|---|
| CoffeeOnce the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of coffee will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices. | Other | Coffee |
| Decaffeinated CoffeeOnce the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of decaffeinated coffee will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices. | Other | Decaffeinated coffee |
| Warm waterOnce the surgical team deems it appropriate to begin a clear liquid diet (in the post-operative period), approximately one cup of warm water will be provided to the patient three times daily. Additives such as cream, milk, sweetener and sugar, will be permitted. The intervention(s) will continue until a change is required as per the treating team or until hospital discharge. Patients will be asked to avoid any additional caffeine intake, such as tea, for the duration of the trial. If a patient receives an NG tube or is placed NPO by the treating team, the intervention will be halted and restarted once a clear liquid diet is restarted. All other aspects of the patients' care will be at the discretion of the treating team as per their standard practices. | Other | Warm water |
Primary outcome
Assessment of accrual
Time frame: 1 year
Average number of patients enrolled per month across the 3 sites for the trial: feasible if 10 or more
Ability to deliver intervention patient is randomized to receive
Time frame: 1 year
Feasible if > 90% of patients receive the correct intervention
Ability to collect complete data for patient-reported outcomes
Time frame: 1 year
Feasible if > 80% of data is collected
Ability to link data from patient-reported outcome measures with Institute for Clinical/Evaluative Sciences and National Surgical Quality Improvement Program datasets
Time frame: 1 year
Feasible if linkage is possible in > 90% of patients
Measurement of baseline data
Time frame: 1 year
1. Median number of hours until flatus in control group 2. Median number of hours until flatus in coffee and decaffeinated coffee groups
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2026.
- Individual participant dataSharing planned: No
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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.
Paul Karanicolas, MD PhD principal investigator
Sunnybrook Health Sciences Centre
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Coffee, Decaffeinated Coffee and Warm water in people with Postoperative Ileus and Caffeine, run by Sunnybrook Health Sciences Centre at 3 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 2 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: finished, as of the sponsor's last update on 12 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 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. 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.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Assessment of accrual (time frame: 1 year). The study lists 5 primary outcomes in all. 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 12 Jan 2026.