Currently, colonoscopy is one of the most used procedures when it comes to the study and
treatment of patients with gastrointestinal conditions, including colorectal cancer,
inflammatory bowel disease, etc.
In the area of colorectal neoplasia, colonoscopy has three main functions, which are to
diagnose the desease itself and prevent its development by detecting and eliminating
potentially premalignant lesions, as well as providing a diagnosis of cancer at an early
stage.
The effectiveness of colonoscopy is crucial to carry out an accurate examination of the
entire colorectal mucosa, which is why the quality of the procedure has been a subject of
study in recent years. Among multiple factors that influence the quality of
colonoscopies, the investigators can mention intestinal preparation, which is essential
for an accurate procedure, because if patients have an inadequate preparation, it could
impair the detection of lesions, since usually, in patients with little or no
preparation, colonoscopy can be either incomplete, which requires the study to be
repeated, or in case the study continues despite poor intestinal preparation, the
presence of feces implies poor visualization of the colonic mucosa, which reduces the
ability to detect lesions such as polyps, especially if they are <5 mm. Therefore, the
type of solution and tolerability, the preparation regimen and the moment in which the
intestinal preparation is performed are considerations to evaluate when performing a
colonoscopy.
The position during the colonoscopy is another factor that can influence colonoscopy´s
effectiveness, and also, the main focus for the investigators to study. Traditionally, if
no position changes occur during colonoscopy, it begins and ends in the left lateral
position. However, recent evidence suggests that supine position may reduce the
disadvantages of the left lateral position, through decreased frequency of position
changes and decreased abdominal pressure, which may result in an easier endoscope
insertion in supine position when comparing it to left lateral position, however, there
is very few information on the optimal insertion technique in colonoscopy, but it has
been observed that in left lateral position, the air leaves the left colon causing it to
collapse and also creating sharp curves that can be difficult to overcome during the
procedure.
As previously mentioned, colonoscopy insertion is technically challenging, and one of the
few clinical trials available that targeted the determination of optimal patient
positioning during colonoscopy insertion compared the supine starting position with the
left lateral starting position, and the investigators found that cecal intubation times
decreased and patient comfort scores improved when using the supine position.
Therefore, patient positioning in colonoscopy has been proposed as a simple and
inexpensive technique to increase luminal distension and improve navigation through the
colon. Based on what has been mentioned before, using the initial supine position could
be a convenient method to reduce cecal intubation time, reduce pain, and improve
acceptance of colonoscopy among patients. However, more research is necessary in this
area to stablish the advantages of the initial supine position over other positions thar
are classically used.
Based on everything that has been described above, the investigators asked themselves the
following research question to start this clinical trial: Is there a significant
difference in the effectiveness and comfort of performing colonoscopy, when comparing the
left lateral position with the supine position?
The institutes where this clinical trial will take place have subjects for study that are
ellegible to enroll as participants, infraestructure and health care providers trained to
perform colonoscopies and a complete investigators team to collect and analyze the data
for this protocol.
The protocol will be limited only to patients who are beneficiaries of each of the
hospitals involved. Furthermore, as it is a single-blind randomized clinical trial, the
endoscopists in the study cannot be blinded, so investigator bias will not be excluded.