Colonoscopies are life-saving way to detect and treat colon or rectal cancer, but they can also be unpleasant or anxiety-inducing for many.
Enter water exchange colonoscopies. Initially introduced decades ago, this innovative method has risen in popularity over the last decade as a safe, potentially sedative-free alternative to traditional colonoscopies.
University of Minnesota Health Gastroenterologist Piet de Groen, MD, is a proponent of the technique. We asked de Groen to tell us more about the benefits of water exchange colonoscopies, how they reduce the need for sedation or narcotics and why they can even be more effective in finding cancer-causing polyps.
Enlarging the colon with air can cause discomfort for patients. A physician performing a colonoscopy needs to use liters of air to inflate the colon, which increases the pressure in the colon. Water exchange colonoscopies don’t require nearly as much water, and the procedure doesn’t put as much pressure on the colon, minimizing discomfort. Water also lubricates the walls of the colon, reducing friction and allowing the scope to easily move through it. The weight of water straightens the colon; air can do the opposite. Additionally, when performing water exchange colonoscopies, doctors frequently do not need to sedate the patient.
Which method is better for the detection of potentially cancerous polyps?
The water exchange colonoscopy is better for the detection of polyps. Water is better than air for cleansing the colon, which improves visibility for the doctor performing the procedure. Water exchange colonoscopies give doctors a better chance to spot difficult-to-see polyps or “flat lesions.” The consensus is that doctors find at least as many—and sometimes more—polyps when using water. Why is this important? For each additional 1 percent of polyps found, there is a 3 percent decrease in interval cancers—or cancers that develop despite a colonoscopy.
Many institutions may charge the same amount for traditional colonoscopies and water exchange colonoscopies, but some factors may make using water more favorable. If an institution charges for the individual components of a colonoscopy, sedation and recovery rooms can both be costly additions. There are other intangible benefits of choosing a procedure that doesn’t require sedation, such as missing less time at work and being able to drive after the procedure. It just disrupts your life less.