Left Lateral Position Versus Supine Position in Colonoscopy

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.