The doctor will stop the procedure and take a tissue sample
If your doctor sees something that looks like cancer during a colonoscopy, they will not remove it right then. Instead, they will take a small piece of tissue—called a biopsy—and send it to a lab. A pathologist (a doctor who studies tissue under a microscope) will examine it to confirm whether it is cancer, what type it is, and how fast it is growing.
The biopsy itself takes only a few seconds. You will not feel pain because the colon has no pain nerves, though you may feel mild pressure. The colonoscopy will end after the biopsy is taken, and you will wake up in the recovery area as the sedative wears off.
You will not know the results that day. The lab usually takes three to seven business days to process the tissue and send a report to your doctor. Your doctor will call you with the results and explain what they mean before discussing next steps.
Key Takeaways
- A tissue sample taken during colonoscopy is sent to a lab to confirm cancer and determine its type and stage.
- Biopsy results typically arrive within three to seven business days, and your doctor will contact you with the findings.
- If cancer is confirmed, your doctor will refer you to an oncologist (a cancer specialist) and order imaging tests to see if it has spread.
- The stage of the cancer—how far it has grown—determines what treatment options are available and what your prognosis may be.
- Many colorectal cancers found during screening are caught early, when treatment is often most effective.
What the biopsy report will tell you
The pathology report describes the cancer in specific terms. It will say what type of cancer it is (almost all colorectal cancers are adenocarcinomas, which start in the cells that line the colon), how deeply it has invaded the colon wall, and the grade—a measure of how abnormal the cells look under the microscope. A lower grade usually means slower growth.
The report will also note whether the cancer appears to be contained to the polyp or whether it has spread into the deeper layers of the colon. This information helps your doctor decide whether more surgery or other treatment is needed. If the cancer is very small and completely removed during the colonoscopy, no further treatment may be necessary—but your doctor will want to confirm this with imaging and possibly a surgical consultation.
Your next appointment: staging and referral
Once cancer is confirmed, your doctor will refer you to an oncologist (a doctor who specializes in cancer treatment). Before you see the oncologist, you will likely have imaging tests—usually a CT scan of your abdomen and pelvis, and sometimes a chest X-ray or CT chest. These tests show whether the cancer has spread to other organs or lymph nodes.
The combination of the biopsy findings and the imaging results determines the stage of your cancer. Stage is numbered from 0 to 4, with higher numbers meaning the cancer has spread further. Your stage guides decisions about surgery, chemotherapy, radiation, or a combination of treatments.
Schedule your oncology appointment as soon as you can after receiving the biopsy results. Most oncologists can see new patients within one to three weeks. Bring the pathology report and any imaging images on a disc or USB drive if your hospital provides them—this speeds up the oncologist's review.
What treatment might look like
Treatment depends on the stage and location of the cancer. Early-stage cancers (stages 0 and 1) that are completely removed during colonoscopy often need only close follow-up with repeat colonoscopies, sometimes with no additional treatment. Stage 2 and 3 cancers usually require surgery to remove the affected section of colon and nearby lymph nodes, often followed by chemotherapy. Stage 4 cancers (those that have spread to distant organs) may involve chemotherapy first, then surgery, or other approaches depending on where the cancer has spread.
Your oncologist will discuss the specific plan for your situation, including the goals of treatment, what to expect during each phase, and potential side effects. Many people benefit from a second opinion before starting treatment—your oncologist expects this and can help arrange it.
Why finding it during screening matters
Colonoscopies are designed to find cancer early, before symptoms appear. Cancers found this way are often at an earlier stage than those found after a person develops symptoms like bleeding, weight loss, or abdominal pain. Earlier-stage cancers generally have better outcomes and more treatment options.
If your colonoscopy found cancer, it means the screening worked—it caught something that needed attention. The fact that you had the procedure puts you in a position to begin treatment sooner rather than later.
Managing the emotional weight
Learning that you have cancer is frightening, even when it was found early. It is normal to feel shock, fear, or anger in the days after diagnosis. Many people find it helpful to bring a family member or friend to appointments to help listen and take notes. Some hospitals have social workers or patient navigators who can help you understand your diagnosis and connect you with support groups or counseling.
Ask your doctor for written information about your specific cancer type and stage. Reading about it on your own timeline, rather than only hearing it in an appointment, can help you process the information and prepare questions for your next visit.
Follow-up after treatment
After treatment ends, you will have regular follow-up appointments with your oncologist to watch for signs that cancer has returned. The schedule varies by stage and type of treatment, but typically includes office visits every few months for the first year or two, along with imaging or blood tests. Your colonoscopy schedule will also change—your gastroenterologist will recommend how often you need screening going forward, which may be different from standard screening intervals.
These follow-up visits are not optional. They are how your doctors catch any recurrence early, when treatment is most effective. Keep all appointments even when you feel well.
Frequently Asked Questions
Will I need surgery if cancer is found during colonoscopy?
Not always. If the cancer is very small and completely removed during the colonoscopy, surgery may not be needed. Your doctor will use the biopsy results and imaging to decide. Larger cancers or those that have invaded deeper layers almost always require surgery to remove the affected section of colon.
How long does it take to get the biopsy results?
Most labs return results within three to seven business days. Your doctor's office will call you with the results rather than mailing them. If you have not heard within a week, call the gastroenterology office to check on the status.
Can cancer be completely removed during the colonoscopy?
Yes, if the cancer is caught very early and is small enough. These are called stage 0 cancers. Your doctor will remove the polyp completely during the procedure. You will still need follow-up imaging and colonoscopies to make sure no cancer remains, but additional surgery may not be necessary.
What should I ask my oncologist at the first appointment?
Ask about the stage of your cancer, what treatment is recommended and why, what the goal of treatment is (cure, control, or symptom relief), what side effects to expect, and how often you will have follow-up visits. Also ask whether a clinical trial might be an option for you.
Will I ever be able to eat normally again after colorectal cancer treatment?
Most people return to a normal diet after surgery and chemotherapy, though this may take weeks or months. Some people experience lasting changes in bowel habits or food tolerance. A dietitian can help you navigate these changes and ensure you are getting adequate nutrition during and after treatment.