What are the guidelines for colonoscopy?

From the Guidelines

Colonoscopy screening should begin at age 45 for average-risk individuals and continue until age 75, with screenings typically performed every 10 years if results are normal, as recommended by the American College of Physicians 1. The preparation process for colonoscopy requires a clear liquid diet the day before the procedure and consumption of a bowel-cleansing solution, typically split into two doses for better results.

• Patients should arrange transportation home as sedation prevents driving for 24 hours after the procedure.
• During the colonoscopy, which takes 30-60 minutes, a flexible tube with a camera examines the entire colon to detect and remove polyps or identify abnormalities.
• The procedure is crucial for colorectal cancer prevention as it allows for removal of precancerous polyps before they develop into cancer, making it both a diagnostic and preventive tool. For those with a family history of colorectal cancer or advanced polyps, screening should start earlier, often at age 40 or 10 years before the youngest affected relative's diagnosis, as suggested by the National Comprehensive Cancer Network 1.
• The quality of the baseline examination can be evaluated to some extent by the number of cancers detected earlier vs later in a surveillance program, highlighting the importance of high-quality baseline performance of colonoscopy 1. Recovery is usually quick, with most people resuming normal activities the following day, though mild bloating or cramping may occur temporarily. It is essential to consider individual risk factors, such as family history and medical assessment, when determining the interval between colonoscopies, as emphasized by the National Comprehensive Cancer Network 1.

From the FDA Drug Label

The preferred method is the “Split-Dose” method and consists of two separate doses: the first dose during the evening before the colonoscopy and the second dose the next day, the morning of the day of the colonoscopy The alternative method is the “Day Before” method and consists of two separate doses: the first dose during the afternoon or early evening before the colonoscopy and the second dose 6 hours later during the evening before the colonoscopy

Colonoscopy Guidelines:

• The Split-Dose regimen is the preferred method, consisting of two separate doses:
  • First dose in the evening before the colonoscopy
  • Second dose the next morning, approximately 5 hours prior to the colonoscopy
• The Day-Before regimen is an alternative method, consisting of two separate doses:
  • First dose in the afternoon or early evening before the colonoscopy
  • Second dose 6 hours later, in the evening before the colonoscopy 2 2

From the Research

Colonoscopy Guidelines

• The U.S. Multi-Society Task Force on Colorectal Cancer recommends colonoscopy every 10 years as a first-tier test for colorectal cancer screening, along with annual fecal immunochemical test (FIT) 3.
• The American College of Gastroenterology, the American Gastroenterological Association, and The American Society for Gastrointestinal Endoscopy support colonoscopy as a cornerstone of screening, regardless of how screening is offered 3.
• A systematic review of colorectal cancer guidelines from various countries suggests that colonoscopy is a frequently recommended screening modality, with screening intervals of every 10 years for average-risk individuals and every 5-10 years for high-risk individuals 4.

Screening Recommendations

• The U.S. Preventive Services Task Force recommends screening for colorectal cancer starting at age 45 for average-risk individuals, with options including high-sensitivity guaiac fecal occult blood test (HSgFOBT), fecal immunochemical test (FIT), multi-target stool DNA (mt-sDNA) test, computed tomographic (CT) colonography, flexible sigmoidoscopy, and traditional colonoscopy 5.
• Individuals with a family history of colorectal cancer or advanced adenoma should undergo screening by colonoscopy every 5 years, beginning 10 years before the age at diagnosis of the youngest affected relative or age 40, whichever is earlier 3.
• A review of CRC screening methods and guidelines suggests that screening should start at age 45-50 for average-risk individuals, with colonoscopy and FIT tests as standard modalities recommended for regular screening 6.

Effectiveness of Colonoscopy

• A study evaluating the effectiveness of colonoscopy, immune fecal occult blood testing, and risk-graded screening strategies in CRC screening found that colonoscopy had a higher detection rate of advanced tumors compared to FIT, but no significant difference compared to a graded screening group 7.
• The study also found that a hierarchical screening strategy based on CRC risk assessment is feasible and can be used as an effective supplement to traditional colonoscopy and FIT screening programs 7.
• The combination of colonoscopy and immune fecal occult blood detection can improve screening accuracy and early detection rates, facilitating early intervention and treatment 7.