Investigation of Cecal Intubation Rates and Pain Levels Between Water Exchange and Air Insufflation Flexible Sigmoidoscopy

Purpose:

This study is being conducted to evaluate whether a new technique, known as the water
exchange technique can more frequently allow for the full colon to be examined in patients
undergoing screening sigmoidoscopy.*

Hypothesis & Goals & Objectives:

It is hypothesised that there will be a 20% or greater difference in cecal intubation rate
(ability for the colonoscope to reach the Ileocecal juncture, and thereby provide full
examination of the colon) at a minimal and acceptable level of discomfort in non-sedated
colon screening patients receiving a scope using the water-exchange method, when compared to
the air insufflation method.

Justification:

Previous studies have shown that the water exchange method is associated with a significant
reduction in discomfort and often allows patients to receive colonoscopy without sedation or
with only minimal sedation. The ability to increase the likelihood of full colon examination
at minimal discomfort has the opportunity to improve upon screening practices and increase
the likelihood of patient participation as discomfort and fear of discomfort is a major
factor that limits uptake of sigmoidoscopy and colonoscopy screening.

Research Design:

This study takes a patient and interviewer blinded and randomised study design. Patients will
be randomly assigned to receive either the water exchange method or the air insufflation
method. Rates of cecal intubation are compared across study arms.

Statistical Analysis Plan:

Effect differences in cecal intubation rates, and responses to whether the scope that they
received was more uncomfortable than they expected, and whether they would be willing to
receive the test again at their next screening interval will be compared using the
Chi-Squared or, when the data necessitates, Fisher's Exact Test. Assuming a non-normal
distribution in reported pain scores, the Mann Whitney U test will be used to assess the
differences in maximum reported pain according to the Wong Baker Faces Pain Rating Scale
between study arms.

*The term sigmoidoscopy is used here as patients are prepared for the procedure using a
standard sigmoidoscopy protocol, rather than colonoscopy. That is, sedation is not
administered; this is a standard practice for sigmoidoscopy procedures but not for
colonoscopy.

Inclusion Criteria:

- Asymptomatic average risk (as per BC colon screening guidelines) individuals

- Ages 50-74 years of age

Exclusion Criteria:

- A sigmoidoscopy or colonoscopy within 10 years,

- A FIT within 2 years,

- Individuals classified with any high-risk screening criteria in accordance to the

BC colon screening guidelines including:

- a personal history of adenoma,

- a first degree relative that was diagnosed with colorectal cancer or multiple adenomas
under the age of 60,

- two or more first degree relatives with colorectal cancer at any age, longstanding
inflammatory bowel diseases,

- a family history of familial adenomatous polyposis or hereditary nonpolyposis
colorectal cancer, - Individuals presenting with rectal pain, rectal bleeding,
abdominal pain, or unintentional weight loss at the time of the examination.