Suggested Searches
View All
View All
View All
General Results

News & Stories

Water exchange colonoscopies reduce discomfort and may lessen the need for sedatives

University of Minnesota Health experts are using an innovative, water-based colonoscopy technique to reduce potential discomfort. The method may also lessen the need for anesthesia or powerful sedatives.
University of Minnesota Health Gastroenterologist Piet de Groen, MD, performs water exchange colonoscopies. This colorectal cancer screening procedure causes less discomfort than traditional colonoscopies and may reduce the need for sedatives or powerful painkillers.

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.

What is a water exchange colonoscopy?

During a water exchange colonoscopy, physicians infuse water in the colon to enlarge it as needed to get a scope from the rectum or anus all the way to the furthest part of the colon, which is the cecum. For years, most doctors have used air to enlarge the colon during a colonoscopy, but water is becoming more popular as more people learn about it and the advantages it offers.

What are those advantages? Why is this your preferred method?

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.

Need to schedule a colonoscopy? Read more about our unique approach.

No sedation is needed?

Correct. The procedure causes less discomfort, so there is often no need for sedation or use of powerful opioid-based narcotics. The method also reduces the risk of “looping,” a potentially painful occurrence during a colonoscopy that raises the risk of complications during the procedure. During a water exchange colonoscopy, I can speak with the patient and tell them what’s happening. They can even follow along on the scope’s video screen as we go. It’s my philosophy that if you don’t need to use anesthesia or narcotics, you shouldn’t.

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.  

Learn more about University of Minnesota Health colon cancer care.

Why isn’t a water exchange colonoscopy standard?

It represents a change in philosophy. Care providers have used air for a long time, and some doctors believe a water exchange procedure is too time consuming. There’s also a skill-set barrier. Many physicians are not trained to perform water exchange colonoscopies. Doctors also have to be comfortable with their patients watching them work. Because the procedure uses minimal to no sedation, patients can follow along on the screen, giving them full transparency. 

What are the financial benefits of a water exchange 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.