Condition category
Digestive System
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
A barium swallow and meal is a type of x-ray that allows doctors to examine the upper gastrointestinal tract (GI), which includes the throat, oesophagus (foodpipe), stomach and duodenum (first part of the small intestine). It is used in diagnosing problems and diseases in these organs. Usually, x-rays will only highlight bone and other parts of the body that block radiation, which makes them easy to see. Before the barium swallow and meal test can be done, the stomach has to be extended with gas to make the pictures as clear as possible. Patients are usually given a fizzy drink called Carbex. This study compares the Carbex with the use of the fizzy soft drinks Indian tonic water and ginger ale. We believe that using soft drinks rather than Carbex will not affect the quality of the test. If the study is successful, it will help us to introduce soft drinks routinely and help to reduce costs to the NHS.

Who can participate?
Patients 18 years and older that have been referred by doctors for a barium swallow and meal to investigate their upper GI tract.

What does the study involve?
Patients are randomly assigned to take either Carbex or a soft drink. If the soft drink does not give clear enough pictures, the patient is given Carbex to drink and the test continued. There are no health implications to this and the aftercare is the same as usual. Patients are then asked to complete a short questionnaire about their experience of the test.

What are the possible benefits and risks of participating?
Patients are likely to enjoy drinking the soft drink more than the Carbex, making the examination a more pleasant experience. Drinking either fizzy drink may cause bloating which can feel uncomfortable in the stomach. This is normal for this examination and is required to produce good pictures.

Where is the study run from?
Torbay Hospital (UK).

When is the study starting and how long is it expected to run for?
The study will run from July to December 2014.

Who is funding the study?
South Devon Healthcare NHS Foundation Trust (UK).

Who is the main contact?
Dr Alexander Crowther

Trial website

Contact information



Primary contact

Dr Alexander Crowther


Contact details

Radiology Department
Torbay Hospital
Lawes Bridge
United Kingdom
+44 (0) 1803 614567

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Comparing soft drink vs Carbex for double contrast upper GI studies: a randomised controlled trial


Study hypothesis

Can a publicly purchased soft drink (i.e. Indian tonic water/ginger ale) achieve comparable distention of the upper gastrointestinal tract in comparison to Carbex during a double contrast barium study and provide a diagnostic study?

On 31/07/2014 the anticipated start date was changed from 01/05/2014 to 18/07/2014.

Ethics approval

NRES Committee South West - Cornwall & Plymouth, 16/07/2014, Ref: 14/SW/0126

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Available on request to


Oral and Gastrointestinal


Participants are randomly allocated to one of two groups
1. Test group - drink soft drink (Indian tonic water or ginger ale) before taking barium
2. Control group - drink Carbex before taking barium
All participants then undergo upper gastrointestinal (GI) tract radiography

Intervention type



Not Applicable

Drug names

Primary outcome measures

1. Is the experimental soft drink used for gaseous distension of the upper GI tract not inferior to the gold standard Carbex against delta at study clinic?
2. Does the experimental soft drink provide a diagnostic upper GI double contrast barium study when used in the place of Carbex at study clinic?

Secondary outcome measures

1. If the soft drink effervescent agent is found to be noninferior then a superiority test will be performed to ascertain whether it is better than Carbex.
2. What are the potential cost savings of using the soft drink over Carbex within this institution and nationwide?
Both assessed at the study clinic

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Any patient referred for an upper GI double contrast GI study and is able to give informed consent.
2. Include any patient over 18 not classified to belonging to a vulnerable group. No upper age limit

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Aged below 18 years of age.
2. Unable to give consent
3. Member of vulnerable group

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Radiology Department
United Kingdom

Sponsor information


South Devon Healthcare NHS Foundation Trust (UK)

Sponsor details

c/o Manager of Research and Development
Research and Development Department
Horizon Centre
Torbay Hospital
Lawes Bridge
United Kingdom
+44 (0) 1803 636635

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

South Devon Healthcare NHS Foundation Trust (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes