Is Colonoscopy Necessary for Everyone?

Colonoscopies are hailed as the golden standard for colon cancer screening. Praised by many as life-saving, more and more physicians are recommending colon cancer screening for everyone, even patients that are considered low-risk.

Are colonoscopies necessary for everyone? Not at all. Only individuals who qualify as high-risk are recommended to have regular screening, and even then, physicians will recommend a schedule that normally doesn’t go beyond once every three years.

Understanding the purpose of colonoscopies and who needs them the most is key to determining whether or not the test is relevant to your health.

What Are Colonoscopies For?

A colonoscopy is a medical examination involving a device called a colonoscope. This device is long and is typically made from thin, flexible plastic with light and camera attachments at the end:


There are three reasons why colonoscopies are performed:

  1. Screening. Routine colonoscopies are recommended to adults ages 50 and above to prevent colon cancer. With screening, patients can understand the state of their colon before symptoms even manifest. This allows doctors to enact on any abnormalities or apply preventative health measures before symptoms begin to appear.
  2. Diagnostic. Colonoscopies characterized as diagnostic are performed to identify suspected issues in the colon. At this point, a patient would already be exhibiting some symptoms such as rectal bleeding, constipation, or intense abdominal pain. The point of the colonoscopy is to reach a conclusive diagnosis of the symptoms since two kinds of disorders may exhibit the same signs.
  3. Surgical. When polyps or growths are found on the colon lining, a colonoscopy is performed to perform a biopsy. With this, a polyp can be removed from the body for further examination.

Colonoscopies are used to diagnose and treat a host of gastrointestinal abnormalities, with colon cancer being the major concern especially for adults 50 and older.

A study from the American College of Physicians affirms how necessary it is to perform routine colonoscopies, showing a  61% decrease in colorectal cancer mortality among veterans under the Veteran Affairs health program (source).

What Can Colonoscopies Detect?

colon colonoscope illustration

Deviant cell behavior can lead to polyp growth along the colon lining. With a colonoscopy, doctors can see, remove, and test the polyp to rule out colon cancer. But that’s not the sole function of a colonoscopy. It can also be used to look for:

  • Crohn’s disease: inflammation of the digestive tract
  • Ulcerative colitis: ulcers in the digestive tract
  • Physical blockages along the colon
  • Diverticulitis: inflammation of small pockets called diverticula on the intestinal wall

What Are the Signs You Need a Colonoscopy?

Inflammations, infections, and abnormal growths along the digestive tract produce a variety of symptoms. When these signs occur, physicians recommend a colonoscopy to reach a definitive diagnosis. Here are some things to watch out for:

  • Irregular bowel movements. Normal bowel movements are regular and easy. Changes in the bowel movement, whether it’s diarrhea or pain during the movement, are all tell-tale signs that something is wrong. Even the shape and color of the stool could be used to tell any abnormalities. Narrow stool are a known sign of polyp growth.
  • Abdominal discomfort. Intestinal cramps and constipation typically go away on their own and are no cause for worry. However, prolonged and persistent episodes of abdominal discomfort can mean that a blockage is present, which prevents the air from circulating through the digestive tract.
  • Rectal bleeding or blood in the stool. Hemorrhoids are the most obvious cause of rectal bleeding, characterized by the presence of bright red blood in the stool. On the other hand, serious gastrointestinal problems may also lead to blood in the stool. It’s crucial to get a colonoscopy once persistent bleeding is observed.
  • Weight loss. Unprecedented weight loss is never a good sign and could point to problems in the gastrointestinal system. When accompanied by other symptoms, weight loss could be a clear sign of blockages or growths in the colon.
  • Constipation. The lingering feeling of needing to have bowel movement, but is not relieved when doing so is characterized as constipation. This symptom is a common sign of polyp growth, or in late stages, colon cancer itself.

Colonoscopy, Aging, and Risks

The Link Between Aging and Risk

The National Foundation for Cancer Research states that 90% of colorectal cancer cases appear in adults ages 50 and older, with the average age of diagnosis at 64 (source). Colon cancer is so prevalent in older individuals that 1 in 4 people will have polyps on their colon by the time they reach 50 years old.

Older adults are at a higher risk of developing colon cancer, or any cancer for that matter, because cell generation slows down with age. Add to that the body’s exposure to alcohol, cigarette, and unhealthy dietary choices during the younger years.

This “older” environment makes it impossible for the body to continually expel unhealthy cells and replace them with new ones, making it conducive for abnormalities to develop at the molecular level.

At What Age Do You Need a Colonoscopy?

The original screening age recommended by the American Cancer Society was 50. Revisions were made due to recent developments concerning rising incidents of colorectal cancer in younger adults. The current recommended screening age has been lowered to 45 (source).

This means that adults aged 45 and above are eligible for a free colonoscopy screening, depending on their insurance plan.

I’m Younger Than 50. Do I Need a Colonoscopy?

People aged 45 years old are now considered at an average risk of developing colon cancer due to recent findings. New research found that colorectal cancer is increasing in both young and middle-aged adults in the US (source).

For adults aged 20 to 39, the lifetime risk of developing colon cancer has increased up to 2% every year from 1990 to 2013. Another study revealed that about 11% of colorectal cancers are diagnosed in adults aged 50 and younger (source).

Although old age remains to be a primary risk in developing colon cancer, the consequences of poor lifestyle choices can also manifest earlier in the form of polyps along the colon lining. Excessive smoking, eating, and a sedentary lifestyle can all lead to greater risk of developing cancer at an early age.

Am I at Risk for Colon Cancer?

Other circumstances unrelated to age may increase the risk of developing colon cancer. These include:

  • Inherited syndromes: Individuals with familial adenomatous polyposis (FAP), Lynch Syndrome, and hereditary non-polyposis colorectal cancer (HNPCC), to name a few are at an increased risk of colon cancer.
  • Family history: Although not hereditary, having a first-degree relative who was diagnosed with the cancer may also influence risk. In this case, doctors typically recommend screening at an even earlier age.
  • Ethnic background: African-Americans and Jews have a higher risk of developing the cancer than other people.
  • Personal history: Diagnosis and even removal of polyps don’t guarantee that patients will remain cancer-free. Regular screening is recommended to patients to prevent recurrence. Similarly, patients with inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis are also considered at a high risk.

Individuals who are considered at a high risk of developing colon cancer are recommended to get a colonoscopy. For average-risk individuals, the recommended frequency is once every ten years, and at least once every two years for those at an above average risk.

Do You Need a Colonoscopy?

colonoscopy screening done by gastroenterologist

Too much of everything can cause problems in your body, and that includes the golden test for colon cancer screening. Diligent screening can prevent cancer and save lives, but too frequent testing is unnecessary and could even cause complications.

Although uncommon, colonoscopies can pose a number of risks when performed unnecessarily:

  • Sedative complications: Sedatives are given to the patient to maximize comfort. Frequent exposure to these chemicals can cause an adverse reaction during the examination.
  • Internal bleeding: In the event a polyp is diagnosed, a tissue sample will be taken for examination. In some cases, this area does not heal and bleeds. This may also happen due to frequent colonoscope insertion.
  • Internal bleeding: In the event a polyp is diagnosed, a tissue sample will be taken for examination. In some cases, this area does not heal and bleeds. This may also happen due to frequent colonoscope insertion.
  • Colon perforation: Tears in the rectum wall can occur in the event that the colonoscope rubs roughly against the colon lining. Also caused by unnecessary colon invasion.  

When Is Colonoscopy Warranted?

Individuals who test negative during a colonoscopy (meaning no polyps were found), have healthy lifestyle choices, and have no pre-existing conditions that may influence polyp growth are considered low risk. They are recommended to undergo another screening after ten years. Anything outside that is considered too intrusive for the colon, which may lead to complications.

On the other hand, individuals with detected or removed polyps are recommended to have their next colonoscopy within 5 to 10 year’s time. This also applies to individuals who are over the age of 45.

We recommend communicating with your gastroenterologist to find out the best colonoscopy frequency specific to your health.

Colonoscopy: Life-Saving Or Bank-Breaking?

Are Colonoscopies Over Prescribed?

Needless medicine prescription, specifically antibiotic, is not new. New reports found that about 30% of tests suggested by doctors are actually unnecessary, with colonoscopies being one of the more targeted tests (source).

It’s sensible for doctors to schedule a follow-up colonoscopy. However, it’s unnecessary to do follow-ups earlier than the guidelines set by the American Cancer Society. Once every ten years is the ideal frequency for those at an average risk, while 1 to 2 times every two to five years depending on the case is recommended for those who are predisposed to cancer.

As mentioned above, unless you qualify as a high-risk individual, there’s absolutely no reason to test more than once every ten years. Lead author Dr. Gina Kruse says that colonoscopies are overused and appeal to patients to be more conscientious regarding recommended tests.

When Not to Have a Colonoscopy?

Out of pocket colonoscopy costs can go up to $10,000 in major cities (Read our post on The Cost of Colonoscopy). Avoid necessary costs by understanding when not to have a colonoscopy. This is applicable when:

  1. A person’s life expectancy is only within 10 years. Colon cancer grows slowly over the course of many years. A colonoscopy may no longer provide any benefit to such patients.
  2. Young patients ages 30 and younger testing for other diseases. Several other non-invasive exams are available to help identify gastrointestinal problems, most commonly inflammatory bowel disease.

When Are Colonoscopies No Longer Necessary?

The good news is that colon cancer risk decreases for people aged 75 and older. This guideline is set by the U.S. Preventive Services Task Force (USPSTF) together with the American College of Physicians (ACP) after determining lower incidence of colon cancer in people within this age group.

This doesn’t apply to patients who are at a high risk. Even at this age, those who were previously diagnosed with polyps or colon cancer have to continue surveillance in order to prevent recurrence.


Unless diagnosed with a polyp or colon cancer, it’s important to treat colonoscopies like any other tests: as preventative measures. When done right, this test can catch colon cancer or even growths before they evolve into cancer.

Stick to the guidelines recommended by various health institutions to ensure that every colonoscopy is beneficial to your health.

Are you ready to get a colonoscopy? Book a consultation today.