Me & My Colon — Colorectal Cancer Screening Guide

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Welcome

Let's Get Started

Colorectal cancer is the second leading cause of cancer death in the United States — yet it is largely preventable with appropriate screening. This tool will help you understand your risk level and the screening options best suited for you.

This survey takes about 3–5 minutes to complete. Your responses are used only to personalize your results.

⚕️ Medical Disclaimer: This tool is for educational purposes only and does not replace advice from your physician or gastroenterologist. Please discuss your results with your healthcare provider.

What is your age? Screening recommendations are based on age and risk factors.

Please enter a valid age between 18 and 100.

Biological sex assigned at birth

Male

Female

Prefer not to say

Please select a response above.

Risk Assessment

Your Health History

Select all that apply. These factors influence your screening schedule and the type of test recommended.

Family history of colorectal cancer or polyps

First-degree relative (parent, sibling, child) with colorectal cancer

Especially if diagnosed before age 60

Two or more first-degree relatives with colorectal cancer

At any age

First-degree relative with advanced adenoma (polyp)

Large, villous, or high-grade dysplasia polyp

Known Lynch syndrome (HNPCC) in the family

Known familial adenomatous polyposis (FAP) in the family

None of the above

Personal medical history

Inflammatory bowel disease (Crohn disease or ulcerative colitis)

Personal history of colorectal polyps (adenomas)

Personal history of colorectal cancer (previously treated)

Previous abdominal or pelvic radiation therapy

None of the above

Lifestyle and other risk factors

Current or former smoker

Obesity (BMI 30 or above)

Heavy alcohol use (more than 2 drinks per day regularly)

High red or processed meat diet

Sedentary lifestyle / low physical activity

Type 2 diabetes

None of the above

🏃 Tell us more about your lifestyle factors

Certain combinations of lifestyle factors affect your risk level and when screening should begin.

Current symptoms Select any you are currently experiencing

Rectal bleeding or blood in stool

Change in bowel habits lasting more than a few weeks

Persistent abdominal cramping or pain

Unexplained weight loss

Unexplained fatigue or weakness

No current symptoms

🚨 Important — Tell us more about your symptoms

Symptoms change the recommendation from screening to diagnostic evaluation. A few more details help clarify urgency.

How long have you been experiencing these symptoms?

A few days

2 to 4 weeks

More than 1 month

Not sure

Has rectal bleeding or blood been visible in your stool?

Yes — bright red blood

Yes — dark or tarry stools

No visible blood

Screening History

Previous Screening Exams

Tell us about any prior colorectal cancer screening you have had.

Have you ever had a colorectal cancer screening test?

Yes

No

Not sure

Your Options

Understanding Colorectal Cancer Screening

Learn why colon cancer is preventable, how each test works, and what accuracy means for you.

Why Screening Saves Lives

Colon Cancer Is Preventable — Here Is Why

Unlike most cancers, colorectal cancer almost always starts as a non-cancerous growth called a polyp — and polyps grow very slowly. This gives us a remarkable window of opportunity: if a polyp is found and removed before it turns into cancer, the cancer never happens. Colonoscopy is the only test that can do both — find the polyp and remove it in the same procedure.

95%

of colorectal cancers begin as a polyp

10-15

years a polyp takes to become cancer

~90%

survival rate when caught at Stage I

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What is a polyp? A polyp is a small clump of cells that grows on the inner lining of the colon. Most are harmless. But a certain type called an adenoma can slowly change into cancer over time. Adenomas are the ones colonoscopy is designed to find and remove.

The Adenoma-to-Carcinoma Sequence

The step-by-step process through which a normal colon cell becomes cancer. Each step takes years — giving screening a chance to interrupt it.

Year 0

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Normal Colon Cell

A healthy cell gets a small DNA change. Nothing visible, no symptoms. This single mutation alone does not cause cancer.

Years 1-5

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Small Adenoma Forms

A tiny polyp — about 1-5 mm, the size of a pencil eraser tip — forms on the colon wall. Still no symptoms. Easy to remove.

Colonoscopy can remove this — cancer prevented

Years 5-10

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Polyp Grows — Dysplasia Appears

The polyp grows to 1-2 cm. Cells begin looking abnormal (dysplasia). Still no cancer, still removable during colonoscopy.

Still removable — colonoscopy stops cancer here

Years 10-15

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Early Cancer — Invades the Wall

Cancer cells push through the mucosa into the submucosa. Stage I — about 90% of patients survive 5+ years when treated now.

Curable — but surgery now required

Years 15-20+

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Advanced Cancer — Spreads to Lymph Nodes or Liver

Cancer spreads beyond the colon wall. Treatment requires surgery, chemotherapy, radiation. 5-year survival drops to ~14% at Stage IV.

Preventable — a polyp was here 10-15 years ago

Medical Illustrations

What a polyp looks like inside the colon

Cross-section showing colon wall layers, a stalked adenoma, and the snare used to remove it.

From polyp to cancer — 4 key steps

Each step takes years. Colonoscopy can stop the process at steps 1 and 2.

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The window of opportunity is wide — but only if you use it. The entire journey from a normal cell to a life-threatening cancer takes 10 to 15 years. A colonoscopy done on schedule can find and eliminate a polyp before it ever becomes cancer. This is true prevention.

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FALSE POSITIVE

Test says something is wrong — but nothing is.

Like a smoke alarm going off from burnt toast when there is no fire. You get an abnormal result, feel worried, and need a follow-up colonoscopy — which turns out to be completely normal. This leads to unnecessary stress and extra procedures.

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FALSE NEGATIVE

Test says everything is fine — but something is wrong.

The smoke alarm stays silent even though there really is a fire. The test misses a real polyp or cancer. You feel reassured, but the problem is still there and growing. This is the more dangerous mistake.

Why this matters when choosing a test: A high false negative rate means the test may miss real problems and give you false reassurance. A high false positive rate means unnecessary follow-up procedures. Colonoscopy has the lowest rates of both — which is why it remains the gold standard. Any positive result on a non-invasive test always requires a follow-up colonoscopy to confirm.

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Colonoscopy

Structural exam — direct visualization

⭐⭐ Gold Standard ▾

A flexible camera-equipped tube passes through the entire colon during a sedated procedure. Polyps can be found and removed in the same session — making it both diagnostic and therapeutic. Preparation involves a bowel cleanse the day before.

Sensitivity — Cancer

~95%

Sensitivity — Adenomas 10mm+

~90-95%

False Negative Rate

~5% (miss rate) — Lowest of all tests

Repeat Interval (Normal)

10 years

Average Cost (uninsured)

$2,500-$4,500

Insurance Coverage

Medicare & most plans — fully covered for screening

⭐ Why it's the gold standard: Colonoscopy is the only test that can visualize, biopsy, and remove polyps in a single procedure. All positive results on other screening tests require colonoscopy for follow-up. A normal colonoscopy provides 10 years of reassurance.

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FIT — Fecal Immunochemical Test

Stool-based — at-home collection

Annual▾

FIT detects hidden blood in the stool using antibodies specific to human hemoglobin. A small stool sample is collected at home and mailed to a lab. No bowel prep or dietary restriction required. A positive FIT must always be followed by a colonoscopy.

Sensitivity — Cancer

~79%

Sensitivity — Advanced Adenoma

~24-40%

Specificity

~94-95%

False Positive Rate

~5-6%

False Negative Rate

~21% for cancer (per single test) HIGH

Repeat Interval

Every year

Cost (uninsured)

~$20-$30

Insurance Coverage

Covered by Medicare & most plans

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Cologuard (Stool DNA + FIT)

Multi-target stool DNA — at-home collection

Every 3 Years▾

Cologuard combines FIT with detection of abnormal DNA methylation shed from colorectal cells. Higher sensitivity than FIT alone but a notably higher false positive rate. Positive results require colonoscopy follow-up.

Sensitivity — Cancer

~92-93%

Sensitivity — Advanced Adenoma

~42-46% LOW

Specificity

~87-90% HIGH FALSE POSITIVE RISK

False Positive Rate HIGH

~10-13% (vs ~5-6% for FIT)

False Negative Rate

~7-8% for cancer

Repeat Interval

Every 3 years

Cost (uninsured)

~$650-$700

Insurance Coverage

Medicare covered; most commercial plans covered

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Blood-Based Tests

Shield (Guardant), ColonSense, others

Emerging▾

Blood-based tests detect circulating tumor DNA shed by cancer cells. Shield (Guardant Health) received FDA approval in 2024 — the first blood test for average-risk CRC screening. Convenient but lower sensitivity than colonoscopy or Cologuard. Positive results require colonoscopy.

Sensitivity — Cancer (Shield)

~83%

Sensitivity — Advanced Adenoma

~13-14% HIGH FALSE NEGATIVE RISK

False Positive Rate

~10% (Shield ECLIPSE trial) HIGH

Repeat Interval

Every 3 years (proposed)

Cost (uninsured)

~$895 (Shield)

Insurance Coverage

Medicare approved 2024; commercial coverage expanding

⚠️ Blood tests detect cancer well but are significantly less sensitive for pre-cancerous polyps (~13-14%). Best suited for patients who decline other options.

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CT Colonography

Virtual colonoscopy — radiologic exam

Every 5 Years▾

CT colonography uses computed tomography to create 3D images of the colon after bowel preparation. Requires full bowel prep but no sedation. Cannot remove polyps — if significant findings are detected, colonoscopy is required.

Sensitivity — Cancer

~96%

Sensitivity — Polyps 10mm+

~88-96%

Repeat Interval

Every 5 years

Cost (uninsured)

~$500-$1,500

Insurance Coverage

Not covered by Medicare for screening; some commercial plans

Understanding Your Test Results

False Positives and False Negatives — In Depth

No screening test is perfect. Every test can make two kinds of mistakes — and the rates differ significantly between tests.

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FALSE POSITIVE

The test says something is wrong — but nothing is wrong.

Imagine your smoke detector going off because someone burned toast — there is no fire, but the alarm still rang. A false positive means the test comes back abnormal, causing worry and a follow-up colonoscopy — but no cancer or polyp is found.

Why it matters: Cologuard has a ~10-13% false positive rate. That means roughly 1 in 8 people who take it will get an abnormal result and need a follow-up colonoscopy that turns out to be unnecessary.

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FALSE NEGATIVE

The test says everything is fine — but something is actually wrong.

The smoke detector stays silent even though there really is a fire. A false negative means the test misses a real problem. You feel reassured, but a polyp or cancer was actually there — and is still growing.

Why it matters: A single FIT test misses about 21% of cancers. This is why annual repeat testing and colonoscopy follow-up for any positive result are so important.

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The bottom line: Colonoscopy has the lowest false negative and false positive rates of any available test, which is why it remains the gold standard. A positive result on any non-invasive test always requires colonoscopy follow-up.

Side-by-Side Comparison

Test	Sensitivity (Cancer)	Sensitivity (Adenoma)	False Positive	Interval	Cost (Uninsured)	Insurance
⭐ Colonoscopy	~95%	~90-95%	Very low	10 years	$2,500-$4,500	Covered
CT Colonography	~96%	~88-96%	Low	5 years	$500-$1,500	Not Medicare
Cologuard	~92% Misses ~8% of cancers	~42-46%	~10-13%	3 years	~$650-$700	Covered
Shield (Blood)	~83% Misses ~17% of cancers	~13%	~10%	3 yrs (proposed)	~$895	Medicare 2024
FIT	~79% Misses ~21% of cancers	~24-40%	~5-6%	1 year	~$20-$30	Covered

Data derived from ACG, USPSTF, ACS screening guidelines, manufacturer pivotal trials, and peer-reviewed literature. Cost estimates vary by geography and insurance.

Your Personalized Results

Your Screening Assessment

Based on your responses, here is your risk level and what is recommended.

The best screening test is the one you actually get done.
Talk to your doctor or gastroenterologist about which option is right for your risk level, personal preferences, and insurance coverage.