Long-term after effects of a colonoscopy

Updated November 22, 2016

Cancer screenings such as a colonoscopy are designed to save lives by finding warnings signs of cancer and stopping the disease from spreading. Some screenings have few side effects or none at all. A colonoscopy is different because it is an invasive test that involves a small camera being pushed through the intestines to look for abnormal growth. It is considered surgery. As with any invasive procedure, colonoscopy is not with risk.

Side Effects of Sedation

Because many people become tense at the idea of a colonoscopy, sedation is used to encourage relaxation. Any time anaesthesia is used, there are risks and side effects. Some of the more serious side effects are blood pressure changes, heart attack and stroke. Anaesthesia can cause death, although that is more likely in someone who is extremely unhealthy going into surgery.

Intenstinal Tears

A colonoscopy is done by moving a tool called a colonoscope through the intestines to look for problems or abnormal growth. One of the risks of doing this is tearing the intestinal wall. Tears are usually minor and the intestines heal quickly in most cases. Usually, within six weeks, the intestinal tears have healed, with no permanent damage. Many people do not even know that they had an intestinal tear from a colonoscopy.

Internal Bleeding

Larger tears may cause internal bleeding after a colonoscopy. Internal bleeding can be fatal, so it is important to look for the signs and go back to the doctor immediately if it is a possibility. Signs of internal bleeding include dizziness and fainting, clammy skin, difficulty breathing, bruising, and swelling across the abdomen. After a colonoscopy, it is extremely important to watch out for these symptoms, because internal bleeding can lead to shock and death if not caught in time. Sometimes, slow bleeding can happen over a long period of time and take a while to be noticeable. In this case, a doctor should be seen as soon as internal bleeding is suspected.

Postpolypectomy Syndrome

A colonoscopy is used to find polyps that have grown in the intestines. When one is found, it is removed during the procedure. This is called a polypectomy. When a polypectomy is done, there is a risk of postpolypectomy syndrome. This is basically an injury resulting from burning the polyp off the intestinal wall. Within a few days or weeks after the procedure, pain and fever will be coupled with a raised white blood cell count. This indicates that the person is suffering from postpolypectomy syndrome.


Death from a colonoscopy is extremely rare. Most of the complications that do lead to death have to do with the removal of polyps found during the colonoscopy and not the procedure itself. A colonoscopy that does not reveal any abnormal growths is extremely safe--and about 1/3 of all colonoscopies do not require polyp removal. Removing the polyps does entail some risk, but the risk of leaving them is greater still, because the polyps can develop into colon cancer. In a Kaiser Institute study conducted from 1994 to 2002, a total of 16,000 colonoscopies were performed and studied. Only one death occurred. In contrast, 50,000 people die of colon cancer each year--a cancer that can be prevented by getting regular colonoscopies.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

R.J. Bowman has a Bachelor's degree in accounting with a minor in English from Pensacola Christian College. After college, she taught English to seventh graders until becoming a mom. At that time, she found freelance writing to be a great way to keep her writing skills sharp.