Colonoscopy After a Positive Shield Test

1. Get the actual report

A positive Shield result needs follow-up colonoscopy. A negative result means the blood test did not detect the signal it was looking for; it does not guarantee that colorectal cancer or an advanced adenoma is absent. Keep those meanings separate from the notification that a report is simply ready to view. [1]

Ask the ordering clinician for the report and the next step. If you see an unfamiliar status in a portal, quote it exactly. "My test is back" does not tell the clinician whether the result is positive, negative, pending, or unavailable.

The purpose of this guide is to help you complete the process. Do not use it to diagnose yourself from a result notification. A screening report starts a follow-up decision; it is not a complete examination of the colon. [1]

2. If it is positive, arrange colonoscopy

A positive test is not the same as a diagnosis of cancer. False-positive results occur, and colonoscopy is the recommended next step to determine what is present. Repeating Shield or choosing a stool test is not the guideline-recommended substitute for that follow-up. [1,2]

Contact the ordering office and ask how the referral will be arranged. Write down which office is responsible, whether it has your result, and what you should do if you do not hear from the scheduling team. If the referral goes somewhere else, keep a copy of the report so you can confirm the receiving team has it.

The ACS recommends timely colonoscopy after a positive noncolonoscopy screening test, preferably within six months. That is not advice to wait six months before calling. Start arranging follow-up when the result arrives, and tell the clinician if the offered appointment is far away. [2]

If you also have symptoms, report them when you call. Blood in the stool, persistent bowel changes, unexplained weight loss, ongoing abdominal discomfort or anemia need assessment in their own right. A routine scheduling pathway should not become a reason to leave those symptoms unmentioned. [3]

What if I feel well?

Feeling well does not remove the need for follow-up. Colorectal cancer and polyps do not always cause symptoms, which is why screening is offered before a person notices a problem. A positive report still needs the recommended examination. [2,3]

3. If it is negative, keep a screening plan

Do not translate "negative" into "my colon is clear." The FDA labeling specifically warns that Shield can miss colorectal cancer and advanced adenomas and tells people with negative results to continue participating in screening. [1]

Ask which test you should use next and when to revisit the plan. If you chose Shield because another method was difficult to complete, say whether that obstacle has changed. Your next screening discussion can revisit the available options rather than automatically repeat the same choice.

Keep the report alongside your other screening records. Future clinicians need the test name and date, not just the recollection that you "had a cancer test." A Shield result and a colonoscopy report describe different examinations and should not be recorded as though they were the same.

What if symptoms start after a negative result?

Contact a clinician about the symptoms. A prior negative blood screen does not explain new bleeding, a persistent bowel change or unexplained weight loss. These symptoms may have other causes, but they need assessment rather than reassurance based only on the screening result. [1,3]

4. If no result is available, clarify what is missing

A missing or unreadable result is not a negative result. Ask the ordering office whether the sample is still being processed, whether a final report exists, or whether the laboratory needs another action. Do not assume a sample problem or arrange a repeat draw from an ambiguous portal label.

The Shield instructions describe laboratory quality controls that must be satisfied before a valid patient result is reported. They do not make an unavailable report evidence that cancer is absent. The laboratory and ordering clinician can explain the specific status on your order. [1]

Guardant estimates results in approximately two weeks. If you are waiting beyond the timeframe the office gave you, follow up with the office instead of treating silence as reassurance. Confirm who will contact you and which telephone number or portal they will use. [4]

5. Close the loop after colonoscopy

Colonoscopy can examine the colon directly and allow removal or biopsy of abnormal tissue. If tissue is sent for examination, ask how you will receive that report as well as the procedure report. [6]

Before considering follow-up complete, make sure you understand the finding and the plan. Ask whether pathology is still pending, who will explain it, and when future screening or surveillance should occur. The endoscopy team should base that plan on the examination and findings, not on a generic interval copied from a screening article.

If the colonoscopy does not find colorectal cancer or an advanced adenoma, review that result with the clinician. Shield can produce false positives and is not a test that identifies the location of any possible noncolorectal cancer. Do not infer another cancer diagnosis from the blood test alone. [1]

How much does follow-up cost?

Medicare says it covers follow-up colonoscopy after a positive blood-based biomarker screen as a screening test, confirmed as of 2026-09-06. Confirm the arrangements and your own benefits before the procedure. Other coverage questions belong with the insurer and the offices involved. [5]

The Shield cost guide includes a billing checklist. The accuracy guide explains why neither a positive nor a negative result is a diagnosis by itself. If you are still deciding whether to be tested, start with our guide to getting Shield online in the US.

Discuss the next step with Well Revolution

Send the actual report, the date of the draw, any current symptoms, and whether a colonoscopy referral is already underway. That makes the conversation about the action still needed. If another office ordered the test, keep it involved so the result and referral do not become separated.

What it costs with Well Revolution

$50 for a prescription. If approved, you will receive a prescription for the Shield lab order and 30 days of support. Guardant runs the test and reports the result. We are there for those 30 days to interpret it, arrange referrals, and treat if needed. Perfect for a single screening test.

Or $90 for the Unlimited Membership. If approved, you will receive 3 months of care with 7 days a week support, plus unlimited prescriptions, lab tests, imaging orders, letters and referrals with same day care, cancel anytime, no fees. Perfect for established patients looking for full care.

Getting started with Well Revolution

Care is chat-based with a licensed provider, same day, no appointment needed. Send your report and the date of the draw, tell us where you are, and we will confirm coverage in your state and set out the next step with you.

References

• [1] Guardant Health / FDA. Shield instructions for use and provider labeling, P230009C. 2024.
• [2] Wolf AMD et al. Colorectal cancer screening: An update to the American Cancer Society guideline, 2026. 2026.
• [3] CDC. Symptoms of Colorectal Cancer. 2026.
• [4] Guardant Health. Completing the Shield test. accessed 2026-09-06.
• [5] Medicare.gov. Blood-based biomarker tests for colorectal cancer (screening). accessed 2026-09-06.
• [6] National Cancer Institute. Screening Tests to Detect Colorectal Cancer and Polyps. accessed 2026-09-06.

Reviewed by PA Michael Rubio, US Medical Director