Frequency of Repeat Colonoscopy in Average Risk Patients



All adults that are at average risk should have a baseline colonoscopy at the age of 50. Certain risk factors may lower the age for a recommended baseline colonoscopy. If you have a clear colonoscopy and no polyps or abnormalities are discovered, you most likely will not have to have another colonoscopy for 10 years.

If your gastroenterologist finds polyps during your colonoscopy, how soon will you have to schedule another procedure? The general guidelines state that a repeat colonoscopy should be performed in five years if one or two small adenomas (precancerous polyps) are found and 10 years if hyperplastic (noncancerous) polyps are found.

The Study

A study in the April issue of Gastrointestinal Endoscopy analyzed the frequency of repeat colonoscopies in Michigan. The lead author of the journal article was Stacy Menees, M.D., of the University of Michigan Health System. She stated, “The aim of our study was to quantify the frequency of appropriate follow-up colonoscopy recommendations after one or two polyps were found during the screening colonoscopy in average risk patients. In addition, we aimed to identify factors associated with adherence to guideline recommendations including bowel preparation quality, demographic factor and procedural factors.”

The study was conducted between January 1, 2009, and December 31, 2009, among average risk individuals aged 50 or over who were undergoing colonoscopy screening and had one to two small polyps. All results were taken from a retrospective endoscopic database from the University of Michigan in-hospital medical procedure unit, two outpatient ambulatory surgery centers and the Ann Arbor Veterans Affairs Health Care System in-hospital endoscopy suite.

The endoscopists (physicians who perform endoscopic procedures like colonoscopies) may sometimes vary from the guidelines. More specifically, the guidelines state that average risk patients with one or two small (less than one centimeter) adenomas (precancerous polyps) at screening colonoscopy should be directed to get a surveillance colonoscopy in 5 to 10 years. If 1 to 2 small hyperplastic (noncancerous) polyps are found, a colonoscopy should be performed in 10 years. Because of the Affordable Care Act, recommending repeat colonoscopies sooner than the guidelines are more scrutinized today, so this study comes at a very appropriate time.

The Results

Of the 922 colonoscopies with 1 or 2 small polyps discovered, 90.2 percent of patients received correct recommendations for appropriate timing for repeat colonoscopies. Eighty-four percent of patients with 1 to 2 small adenomas and 94 percent of patients with 1 or 2 hyperplastic polyps received recommendations consistent with guidelines.

What would make endoscopists vary from the recommended timing for repeat procedures? A colonoscopy could be recommended sooner if:

  • Bowel prep was fair or poor because polyps or adenomas could be missed
  • Patient is at higher risk for colorectal cancer
  • Patient is older than age 70
  • The endoscopist is concerned about limitations of the colonoscopy in preventing colorectal cancer on the right side
  • Endoscopist distrusts research that supports the guideline recommendations