A colonoscopy is a procedure used to directly visualize the colon. The physician inserts a camera connected to a tube inside the anus and into the large intestine. The procedure is able to detect ulcers, abnormal growths and inflamed tissue. A colonoscopy is used to screen for the early signs of colon cancer. The procedure is relatively safe, but there are some complications associated with it.
Perforation
Perforation is a traumatic tear in the walls of a hollow organ. Perforation of the large intestine may occur when the tube used in a colonoscopy accidentally punctures the lining of the large intestine. Perforation can either be small or large. Small tears are caused when the colonoscope, the tube and camera, cause a small tear in the intestines by pushing up against the healthy tissue. Small perforations are much more likely when the surgeon takes a biopsy during the procedure.
Large perforations are just as common as smaller tears. Often, patients have a bowel loop that has been stretched due to abnormal deformations or other defects. Larger perforations are dangerous because they are very difficult to detect during the procedure and can lead to infection or sepsis.
Adverse Reaction to Anesthesia
Anesthesia or other forms of sedation are often used to calm and numb the patient during a colonoscopy. Patients can have an adverse reaction to the medication used for the sedation. Patients may suffer from respiratory depression, a severely decreased heart rate, low blood pressure and a decrease in oxygen content of the blood. All of these effects are caused by the anesthesia’s ability to affect the muscles and nerves of the body. If these complications become severe the patient may not survive the colonoscopy. An adverse reaction to anesthesia is extremely rare.
Bleeding
Small amounts of blood in the stool may not be a complication, but rather a minor side effect of the procedure. Bleeding only becomes a complication when it is so severe that the patient requires medical attention for the hemorrhage. Usually, large hemorrhages are immediate and easily evident during the colonoscopy. However, some bleeds are not noticed until several hours or even days after the procedure. The incidence of this complication is between 0.1 percent and 2 percent, according to Dr. Stephen M. Kavic and Dr. Marc D. Basson in their article "Management of Complications of Colonoscopy" in "Surgical Treatment: Evidence-Based and Problem-Oriented."
