You had a colonoscopy, and the report came back saying polyps were found. Maybe one, maybe several. Maybe the doctor mentioned words like tubular adenoma or sessile serrated lesion and moved on before you could ask what any of it meant. If you left the appointment with more questions than answers, you are not alone.
The good news is that most polyps found during routine colonoscopy are benign, and finding them is precisely the point of the screening. But not all polyps are created equal. Size, cell type, and the number found all factor into how closely your doctor will want to watch you going forward. Here is a plain-English guide to what those findings usually mean.
What Is a Polyp, Exactly?
A polyp is simply an abnormal growth of tissue on the inner lining of the colon or rectum. Think of it as a small bump or protrusion that develops when cells multiply more than they should. Most polyps cause no symptoms, which is why colonoscopy—where a camera inspects the entire colon—is the primary way they are found.
Not every polyp has meaningful cancer risk. Many are completely harmless and would never cause problems. Others have the potential, over many years, to change into cancer if left in place. The job of your gastroenterologist is to remove them during the colonoscopy (a painless snip or burn at the time of the procedure) and then look at the tissue under a microscope to figure out what you are actually dealing with.
Type: The Most Important Factor
Pathology—the laboratory analysis of the removed tissue—tells your doctor what kind of cells make up the polyp. This is the single most important piece of information in your report.
Hyperplastic polyps are the most common type and are generally considered low-risk. They are made up of normal-looking cells that have simply piled up a bit. When hyperplastic polyps are small and located in the lower part of the colon, most guidelines treat them similarly to finding nothing at all.
Adenomas are the polyps that get the most attention from doctors, and for good reason. They are the type most closely linked to colorectal cancer over time. An adenoma is a glandular growth that, under the right conditions, can slowly accumulate genetic changes and eventually turn malignant—a process that typically takes a decade or more. Because of this potential, adenomas are sometimes called precancerous, though that word can feel scarier than the situation usually warrants. The vast majority of adenomas are removed completely and never become cancer.
Within adenomas, pathologists make a further distinction based on the pattern of cells:
- Tubular adenomas have a more regular, tube-like cell arrangement and carry lower risk.
- Villous adenomas have finger-like projections and are associated with higher risk.
- Tubulovillous adenomas fall somewhere in between.
Another important descriptor is dysplasia, which refers to how abnormal the cells look. Low-grade dysplasia means the cells look only mildly abnormal. High-grade dysplasia means the cellular changes are more pronounced—a signal to follow up more aggressively, even though high-grade dysplasia is still not the same as cancer.
Serrated polyps are a family of growths that have received growing attention from researchers in recent years. Some serrated polyps, particularly sessile serrated lesions (sometimes called sessile serrated adenomas), can develop into cancer through a different biological pathway than traditional adenomas. They tend to be flat and pale, making them harder to spot during colonoscopy, and they can progress more quickly than typical adenomas. Their discovery often leads to a shorter recommended follow-up interval.
Size: Bigger Generally Means More Attention
Polyp size is measured in millimeters and recorded in your pathology report. Gastroenterologists often use a rough shorthand:
- Diminutive polyps measure 5 millimeters or less—about the size of a pencil eraser tip.
- Small polyps are 6 to 9 millimeters.
- Large polyps are 10 millimeters (1 centimeter) or more.
Size matters because larger polyps have had more time to accumulate changes and are statistically more likely to contain areas of advanced or high-grade tissue. A large adenoma—sometimes called an advanced adenoma—typically triggers a recommendation for a repeat colonoscopy sooner than a small one would.
That said, size alone does not tell the whole story. A tiny serrated lesion in the right side of the colon may warrant closer surveillance than a small tubular adenoma, depending on location and other features. Your doctor weighs several variables together.
Number: More Polyps, More Vigilance
Finding one small, low-risk polyp is a very different situation from finding several. Current clinical guidelines generally use the number of adenomas found to help set the next colonoscopy interval.
Patients who have one or two small, low-grade tubular adenomas removed are typically considered lower risk and may be advised to return for a follow-up colonoscopy in several years. Those with three or more adenomas, or with any single advanced adenoma, are often placed on a shorter surveillance schedule. Finding ten or more adenomas in a single colonoscopy can prompt evaluation for rare hereditary conditions that cause polyps to grow in large numbers throughout the gastrointestinal tract.
It is also worth noting that the quality of the colonoscopy itself matters. If the bowel preparation was poor and the doctor could not see every fold of the colon clearly, there is a chance some polyps were missed. A thorough, well-prepared colonoscopy gives a more reliable picture.
Shape and Location: Two More Pieces of the Puzzle
Polyps come in different shapes. Pedunculated polyps grow on a stalk, like a mushroom. Sessile polyps sit flat against the colon wall. Flat or sessile growths can be harder to remove completely in one piece, and incomplete removal raises the question of whether cells remain behind.
Location in the colon also plays a role. The colon is divided into the right side (ascending colon) and the left side (descending colon and sigmoid) with the transverse colon in the middle. Some research suggests that right-sided serrated lesions may behave differently than left-sided polyps, which is one reason your report may specify where each polyp was found.
What Happens After Polyps Are Removed?
When a polyp is removed during colonoscopy, the goal is complete excision—getting all of the abnormal tissue out. The pathology report will often note whether the margins (the edges of the removed piece) appear clear of abnormal cells. If a polyp was large or had to be removed in multiple pieces, your doctor may recommend a follow-up colonoscopy sooner to confirm the area has healed cleanly.
Going forward, your surveillance schedule—how often you return for a repeat colonoscopy—is determined by a combination of everything above: type, grade, size, number, completeness of removal, and sometimes your personal or family history of colorectal cancer. Guidelines from major gastroenterology societies provide a framework, but your doctor tailors the recommendation to your specific findings.
A note on family history: If a close relative—a parent, sibling, or child—was diagnosed with colorectal cancer or advanced polyps, mention it to your gastroenterologist if you have not already. Family history can shift the recommended starting age and frequency of screening, independent of what your own colonoscopy found.
What You Can Do Between Colonoscopies
Surveillance colonoscopy is an important safety net, but lifestyle choices also influence polyp risk. Research consistently links higher intake of red and processed meat, smoking, heavy alcohol use, obesity, and physical inactivity to increased colorectal cancer risk. On the other side, regular physical activity, a diet rich in vegetables and fiber, and maintaining a healthy weight are associated in observational studies with lower risk. These are not guarantees, but they are modifiable factors worth discussing with your primary care doctor.
When to Call Your Doctor
Polyp removal is generally safe, but let your care team know if you experience heavy rectal bleeding, severe abdominal pain, fever, or chills after a colonoscopy. These are uncommon but warrant prompt attention.
And if your pathology report still feels confusing after reading this—ask. You have every right to request a phone call or follow-up appointment specifically to go over the results. Ask your gastroenterologist what type of polyps were found, whether any were considered advanced, and exactly when you should schedule your next colonoscopy. Writing those answers down or asking for them in your patient portal ensures you do not have to rely on memory alone.
The Bottom Line
A colonoscopy that finds polyps is doing exactly what it is supposed to do. Polyps removed before they have a chance to progress cannot become cancer. The details in your report—type, size, number, shape, and location—are the inputs your doctor uses to build a personalized surveillance plan that keeps you protected going forward. Understanding those details does not require a medical degree; it just requires asking the right questions and staying on schedule for your next visit.