Water Immersion

Frequently Asked Questions (FAQ)

Water immersion colonoscopy is an innovation to the method of performing colonoscopy that makes substantial changes to the insertion phase of the test such that the procedure can be performed without the need for anesthesia. In the traditional method, air is used during inserting the scope to permit the doctor to visualize the colon walls as the scope is advanced. Without adding the air, the doctor would not be able to see forward such that they can determine which direction to proceed. It is necessary to see ahead to avoid putting excessive pressure against the colon wall. The slow but steady addition of air causes the colon to be far longer and makes the folds and turns sharper. Imagine one of the spaghetti balloons used by the clowns at the circus to make into various animals. The balloon starts out only six inches, but with the addition of air, the balloon becomes several feet long and can be twisted into animal shapes. Only in the abdomen, the space is limited and the larger inflated colon becomes full of twists and turns. These sharp turns make advancing the tube to the end (where the appendix resides) very difficult and uncomfortable. When the air is inserted to improve vision ahead, the air doesn’t stay limited to the area where the tip of the colonoscope resides, it distributes throughout the entire colon.

The more air infused, the more the elongated colon must fold into compact sharp turns to fit in a fixed space. In water immersion, no air is employed during scope insertion. Instead, small bursts of water are used, which inflates the area at the tip of the scope where we need to be able to see, but is not distributed evenly throughout the five feet of colon. The water does not spread out nearly as much as air, so the volume added to complete the test is far less and the colon is not made longer during insertion. The end result is that the scope floats through the gentle twists and turns and the level of discomfort is greatly reduced. The pain is so little that most patients can complete the test without use of major anesthesia medications. No narcotics, no sedatives, no propofol. The patient is awake for the entire procedure and can watch as the colon is examined and if any polyps seen, removed. Removing polyps from the colon does not cause any discomfort since there are no pain nerves in the colon. The only nerves in the colon respond to stretch and distention.

The usual description of pain in the colon relate to “gas” pains. But the cutting and cauterizing of polyps does not generate any pain whatsoever. With the replacing of air to distend the colon with water, the test becomes far less uncomfortable and can be performed with the need for an anesthesia provider. Once the scope has been advanced to the end of the colon, air is used to gently inflate the tube, but far less is necessary, and the air is removed as the scope is withdrawn. We have performed hundreds of water immersion colonoscopies and continue to be amazed by how well it is tolerated by the patient. Only two patients were unable to complete the test. Most patients are pleasantly surprised at how little pain they experience and plan to employ water immersion for their future colonoscopy tests.