In short
Most polyps are harmless, but most colon cancers begin as one — which is why removing them is the point of the procedure. The report's least-read line, how good the bowel preparation was, decides how much the rest can be trusted.
Emergency if: Heavy rectal bleeding, severe or worsening abdominal pain, a hard swollen abdomen, or fever in the days after a colonoscopy — go to an emergency department now.
On your report
Hemoglobin, Ferritin, CEA (Carcinoembryonic Antigen), CRP +2 more
On this page
01
Looking and removing in one visit
A colonoscopy examines the lining of the large bowel with a flexible camera, and can identify irritated and swollen tissue, ulcers, polyps and cancer. Its distinctive feature is that it treats as well as looks: polyps found during the examination are removed at the same time, and you will not feel it.
That is why it is a preventive procedure rather than only a diagnostic one. Polyps are common in adults and are harmless in most cases, but most colon cancers begin as a polyp, so removing polyps early may help prevent cancer.
02
The preparation score, and why it decides everything
Reports state how clean the bowel was, often using a formal scale. This is the most consequential line on the page and the one patients skip. A poorly prepared bowel hides flat and small polyps, and the examination cannot be better than the view it had.
If preparation is described as poor or inadequate, the recommended repeat is usually much sooner — often within a year — regardless of what was or was not found. A report that says the caecum was reached with good preparation is the combination that makes a clear result genuinely reassuring.
03
Polyp types on the pathology report
The appearance at the time is provisional; the pathology report a few days later is what counts. Hyperplastic polyps, particularly small ones in the lower bowel, carry essentially no cancer risk. Adenomas are the ones that matter, because they are the lesions that can, over years, become cancer — which is precisely why removing them works.
Adenomas are further described by size, number, and whether they show villous features or high-grade dysplasia. Sessile serrated lesions are a separate group that are flat, harder to see, and taken seriously despite looking innocuous. A report saying an adenoma was completely removed is a good outcome, not a worrying one.
04
How the next interval is set
The date for your next colonoscopy is calculated from what was found: how many polyps, how big, what type, whether removal was complete, and how good the preparation was. One or two small low-risk adenomas lead to a long interval; multiple, large, or higher-risk lesions lead to a much shorter one. Family history and inflammatory bowel disease shift it again.
Screening for colorectal cancer is generally recommended from age 45, and people at higher risk may be advised to start younger and be examined more often. Ask for your next due date in writing and record it, because the interval can run to years and is easily lost between appointments.
05
Normal, and what it does not cover
A complete colonoscopy with good preparation and no polyps is a strong result, and for most people it means no repeat for a long interval. It does not, however, explain symptoms it was not designed to explain: irritable bowel syndrome, coeliac disease, bile acid diarrhoea and thyroid disease all produce bowel symptoms with a normal colonoscopy.
Continuing symptoms after a clear examination should be taken back to the doctor rather than treated as disproved. Persistent bleeding after a normal colonoscopy in particular deserves a fresh look rather than reassurance, because the commonest reason is a source the examination did not cover.
06
Risks, and afterwards
Complications are uncommon and quantified: bleeding occurs in about 15 out of every 10,000 procedures and perforation in about 3 out of every 10,000. Those numbers are worth holding alongside the fact that the procedure prevents cancers, particularly when someone is weighing whether to attend.
Cramping and wind for a few hours afterwards are expected, and a little blood after polyp removal can be normal. Heavy or continuing bleeding, severe or worsening abdominal pain, a hard swollen abdomen, or fever in the days after the procedure are not, and need urgent assessment.
When to act
Routine — see a doctor
A complete examination with good preparation and one or two small polyps removed: note the next due date from the report and keep it somewhere you will find it.
Same-day — call promptly
Preparation reported as poor or inadequate, or bleeding that continues after the procedure — both need a plan rather than waiting for the next routine appointment.
Emergency — act now
Heavy rectal bleeding, severe or worsening abdominal pain, a hard swollen abdomen, or fever in the days after a colonoscopy — go to an emergency department now.
Values mentioned in this story
Each one opens a visual guide with its normal range and what moves it — upload a report and we place your own numbers on the same scale.
Sources
- Colonoscopy — NIDDKniddk.nih.gov
- Colonoscopy — NHSnhs.uk
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