Colonoscopy

Primary indications for colonoscopy as a colorectal cancer (CRC) screening tool (2025 guidelines):

  • Average-risk adults: Ages 45–75 years (per ACG and USPSTF).

  • High-risk individuals: First-degree relative with CRC or advanced adenoma → start at 40 years, or 10 years before the earliest family diagnosis (whichever comes first).

  • Surveillance:

    • Every 10 years for average-risk individuals with a normal exam.

    • Every 5 years for high-risk individuals.

Key Indications for Colonoscopy in CRC Screening

Average-risk, asymptomatic adults

  • Start Age: 45–75 years

  • Frequency: Every 10 years

  • Notes: Some guidelines still mention 50, but 45 is now standard.

High-risk (family history of CRC/advanced adenoma)

  • Start Age: 40 years or 10 years before earliest family case

  • Frequency: Every 5 years

  • Notes: Applies to first-degree relatives.

Personal history of adenoma or CRC

  • Start Age: After polypectomy or resection

  • Frequency: Per surveillance protocol

  • Notes: Follow-up, not primary screening.

Inflammatory Bowel Disease (IBD)

  • Start Age: 8–10 years after symptom onset

  • Frequency: Every 1–3 years

  • Notes: For ulcerative colitis or Crohn’s colitis.

Additional Context

  • Not routinely recommended in adults >75 or those with life expectancy <10 years.

  • Colonoscopy is the gold standard due to both detection and prevention (polyp removal).

  • Alternatives include FIT and sigmoidoscopy, but colonoscopy is the only one-step test.

  • Based on ACG, USPSTF, and international consensus guidelines.

Summary:

  • Average-risk: Start at 45, repeat every 10 years until 75.

  • High-risk: Start at 40 or 10 years before family case, repeat every 5 years.

  • Other groups: History of adenoma/CRC or IBD → follow surveillance protocols.

Cologuard (mt-sDNA)

Cologuard is an FDA-approved, non-invasive stool DNA test for average-risk adults ages 45–75.

Key details:

  • Indication: Average-risk, asymptomatic adults with no strong family or personal history.

  • Interval: Every 1–3 years (USPSTF & AAFP).

  • How it works: Detects occult blood + DNA mutations/methylation linked to CRC and advanced adenomas.

  • If positive: Follow-up diagnostic colonoscopy required.

  • Not for: High-risk patients (CRC history, adenomas, IBD, strong family history).

Comparison of Stool-Based CRC Screening Tests

FIT (Fecal Immunochemical Test)

  • Interval: Annually

  • Sensitivity: Moderate

  • Positive → Colonoscopy

  • Risk Group: Average-risk, 45–75

gFOBT (Guaiac Fecal Occult Blood Test)

  • Interval: Annually

  • Sensitivity: Moderate

  • Positive → Colonoscopy

  • Risk Group: Average-risk, 45–75

Cologuard (mt-sDNA)

  • Interval: Every 1–3 years

  • Sensitivity: Higher than FIT

  • Positive → Colonoscopy

  • Risk Group: Average-risk, 45–75

Clinical Guidance

  • Cologuard is a valid alternative for patients unwilling or unable to undergo colonoscopy.

  • Colonoscopy remains the preferred test due to its diagnostic and therapeutic benefits.

Colon Cancer Q & A (Patient-Facing Content)

<img class=”alignright size-full wp-image-692″ src=”/wp-content/uploads/2020/03/colon.jpg” alt=”Colonoscopy screening” width=”30%”>

Every year, around 135,000 Americans are diagnosed with colon cancer. At Los Angeles Integrative Gastroenterology & Nutrition in Century City, Farshid Sam Rahbar, MD, FACP, ABIHM, a board-certified internist and gastroenterologist, provides expert diagnosis and treatment with a holistic, integrative approach that supports overall health while fighting disease.

📞 Call (310) 289-8000 or schedule an appointment online today.

Q: What is colon cancer?
A: Colon cancer (colorectal cancer) begins in the large intestine, usually from polyps that may turn cancerous. Symptoms include:

  • Changes in bowel habits

  • Blood in stools or rectal bleeding

  • Abdominal pain, cramping, or gas

  • Feeling of incomplete bowel emptying

  • Unexplained weight loss

Early stages may be asymptomatic, making screening essential.

Q: How is colon cancer diagnosed?
A: Colonoscopy is the gold standard. Dr. Rahbar uses a thin, flexible colonoscope with a camera to examine the colon, remove polyps, and take biopsies if needed. The procedure is outpatient, with sedation for comfort.

Q: How is colon cancer treated?
A: Treatment depends on stage and health status. Early cancers may be treated during colonoscopy (polyp removal). Advanced disease may require surgery, chemotherapy, or radiation. Dr. Rahbar integrates conventional care with holistic medicine to support recovery and overall wellness.

👉 If you’re due for screening or have concerns, call or book a consultation online today.