Colonoscopy: When and Why Would You Need to Follow Up
A colonoscopy is the most preferred diagnostic and screening procedure for colorectal cancer in the world. Why? Physicians prefer a colonoscopy over other screening methods mainly because it allows the doctor to visualize the entire colon to detect and remove possible precancerous growths known as polyps. The American Academy of Family Physicians states that a single normal colonoscopy lowers your colorectal cancer mortality risk by 68% when compared to the general population. If you are awaiting a colonoscopy or your follow-up appointment after your colonoscopy, it is natural to feel nervous about your results. You may also wonder when your next colonoscopy will occur depending on how your procedure went. In this article, you will learn about when and why you would need a follow up after a colonoscopy and what determines the intervals between your screenings.
How Results Affect the Timing of Your Next Colonoscopy
Typically, you will find out the results of your colonoscopy directly after your procedure. If your gastroenterologist does not find any polyps, abnormal tissue, or inflamed areas then you most likely will be told you have a normal colonoscopy or a negative result. A normal colonoscopy usually means that you are at a low-risk for developing colon cancer and will not need another colonoscopy for between 5-10 years from this one. However, if your gastroenterologist tells you that you had a positive result or finding during the procedure you most likely will be asked to get a colonoscopy sooner.
A positive result from a colonoscopy is a relatively common occurrence and signifies that your physician found a polyp or a form of abnormal tissue in your colon. Polyps are very common and often benign, or noncancerous.
A positive result from a colonoscopy is a relatively common occurrence and signifies that your physician found a polyp or a form of abnormal tissue in your colon and most likely removed the polyp during the procedure. Polyps are very common and often benign, or noncancerous. While a polyp usually is benign, some polyps are precancerous and are called adenomas. These types of polyps develop into colon cancer with time. This is why your physician aims to remove any and all polyps detected in the colonoscopy and biopsy the tissue for cancer.
Your physician will ask you to get a follow up colonoscopy sooner than people at low risk for colon cancer for the following reasons:
Large polyps. Polyps more than one centimeter in diameter may increase a person’s risk for colon cancer.
Multiple polyps. While the majority of polyps are benign and will not develop into cancer, the detection of more than two polyps and especially many small ones also increase a person’s risk for developing colon cancer.
Adenoma. An adenoma is a polyp that is highly likely to be precancerous. You are at an increased risk for colon cancer if your physician finds an adenoma and will most likely be asked to get more frequent screenings. For example, a finding of more than ten adenomas places a patient in the highest risk category and usually requires a colonoscopy every year.
Follow Up Timeline Factors
After your colonoscopy, you will return to your physician for a follow-up appointment. At this appointment, you will discuss with your doctor recommendations he or she may have and refer you to a specialist depending on what was diagnosed during your procedure. The time interval between screening colonoscopies depends on a few factors. These include:
- Personal history of colon cancer
- Personal history of familial adenomatous polyposis or Lynch syndrome
- Personal history of irritable bowel syndrome (IBS) such as Crohn’s disease or ulcerative colitis
- Past history of polyps or abnormal tissue findings during a colonoscopy
- Family history of colorectal cancer
- Results from your last colonoscopy
If you had a polyp or polyps removed during your colonoscopy, be prepared for a repeat colonoscopy within the decade. The timing of your next colonoscopy depends on the size and number of polyps found. Generally, if your physician finds and removes one to two polyps small in size (less than 1 centimeter in diameter) you will be asked to have another colonoscopy in another five to ten years.
The interval between your next colonoscopy may be sooner if your colonoscopy revealed the following:
- Two or more polyps were detected
- Pathology report show cells from polyps have a high risk of developing into cancer
- Improper bowel cleansing with polyps found
- A large polyp (greater than 1 centimeter in diameter) was detected
- Pathology report reveal cancerous polyps
Your results from the colonoscopy play a role in the determination of your next screening colonoscopy. A negative result usually means that you will follow a regular screening schedule determined by the following:
- Your age
- Your health history
- Your genetic factors
A positive result from your colonoscopy will change the way your physician handles your case, especially the timing of your follow up colonoscopy. If your biopsy was returned with a pathology report of precancerous or cancerous cells then you may need additional procedures and treatment to remove all precancerous/cancerous growths.
The following timeline is intended for reference only, your physician will recommend the appropriate timing of your follow up colonoscopy depending on your health history, results from your colonoscopy, and other factors that play into your health plan.
Follow Up Schedule For Low Risk Patients
You are considered low risk for colorectal cancer for the following reasons:
- Last colonoscopy was normal (or a negative result)
- No personal or family history of colorectal cancer
- No personal history of polyps
- No personal or family history of IBS (such as Crohn’s disease)
- No personal or family history of Lynch syndrome or familial adenomatous polyposis
Low risk patients are recommended to have a follow up colonoscopy every 10 years.
Follow Up Schedule For High Risk Patients
One of the major reasons you will be asked to get a follow up colonoscopy sooner that the average risk patients is if a polyp, adenoma, or multiple polyps were found in your screening colonoscopy.
You are considered high risk for colorectal cancer for the following reasons:
- Personal or family history of colorectal cancer
- Personal or family history of familial adenomatous polyposis
- Personal or family history of inflammatory bowel disease
- Personal history of polyps, adenomas, or multiple polyps
High risk patients will typically be asked to get a colonoscopy in much shorter intervals than the low or average risk patients. One of the major reasons you will be asked to get a follow up colonoscopy sooner that the average risk patients is if a polyp, adenoma, or multiple polyps were found in your screening colonoscopy. If you had a polyp or multiple polyps removed, your follow up colonoscopy depends on size, shape, and number of polyps detected.
These intervals are as follows:
Adenoma size and number
1-2 adenomas (tubular) less than 1 cm in diameter – 7-10 years
2-4 adenomas (tubular) less than 1 cm in diameter – 3-5 years
5-10 adenomas (tubular) less than 1 cm in diameter – 3 years
Single adenoma greater than 1 cm in diameter – 3 years
Single adenoma (tubulovillous or villous) – 3 years
Single adenoma high-grade dysplasia* – 3 years
*dysplasia refers to cells that look like they may be cancerous
More than 10 adenomas – every year
Adenoma larger than 2 cm in diameter – six months
Ford, B. (2021, March 01). Colonoscopy follow-up: U.S. Multi-Society Task Force on colorectal cancer updates recommendations. American Family Physician, 1013(5), 314-316. Retrieved from AAFP: https://www.aafp.org/afp/2021/0301/p314.html
Gupta, S., et. al. (2020). Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology, 158(4), 1131-1153.e5. Retrieved from Gastro Journal: https://www.gastrojournal.org/action/showPdf?pii=S0016-5085%2819%2941479-0
Shmerling, R. H. (2020, October 14). Understanding the results of your colonoscopy. Retrieved from Harvard Health: https://www.health.harvard.edu/staying-healthy/understanding-the-results-of-your-colonoscopy