Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Characterise colorectal polyps accurately, secure complete and safe excision, interpret pathology and procedural quality together, and apply UK post-polypectomy surveillance without unnecessary colonoscopy.
Colorectal polyps arise through several biological pathways. Conventional adenomas are tubular, tubulovillous or villous neoplasms and are graded for dysplasia. Serrated lesions include hyperplastic polyps, sessile serrated lesions and traditional serrated adenomas; size, proximal site and dysplasia influence risk. The endoscopist describes location, diameter against a calibrated reference, Paris morphology, surface and vascular features, lifting characteristics and whether removal was en bloc or piecemeal. Pathology then reports type, dysplasia, invasive cancer if present and margin confidence where evaluable. A rounded label such as ‘benign polyp’ loses the details that determine surveillance and whether cancer resection was adequate.
Polypectomy aims for complete excision with the safest effective technique. Diminutive lesions may be removed by cold snare, while larger lesions require planned endoscopic mucosal resection, endoscopic submucosal dissection, full-thickness resection or surgery according to morphology, invasion risk and expertise. Tattoo placement helps later localisation but must be positioned so it does not create submucosal fibrosis beneath a lesion awaiting advanced resection. Suspected deep invasion, non-lifting without prior manipulation, ulceration or an adverse optical pattern should trigger expert discussion, because piecemeal removal destroys pathological staging and may seed fibrosis that makes definitive treatment harder. Pedunculated lesions require assessment of head and stalk, bleeding risk and margin.
A tubular, tubulovillous or villous lesion with low- or high-grade dysplasia enters premalignant-polyp counting; size and high-grade dysplasia determine whether it is advanced for surveillance criteria.
A subtle flat proximal lesion with mucus cap and indistinct margins can be missed. Size at least 10 mm or any dysplasia makes it advanced in the BSG surveillance definition.
Ulceration, induration, convergence, depressed morphology, disrupted vascular pattern or convincing non-lifting raises submucosal cancer and should prevent casual piecemeal resection.
Five or more premalignant polyps, or at least two with one advanced lesion, meets the BSG high-risk post-polypectomy threshold after complete clearance and high-quality examination.
Ten or more cumulative adenomas, numerous serrated lesions or young-age multiplicity should prompt hereditary-risk assessment rather than repeated use of the average-risk surveillance algorithm.
Immediate or delayed bleeding, escalating abdominal pain, fever, tachycardia or peritonism after resection raises haemorrhage, perforation or electrocoagulation syndrome and needs acute reassessment.
Check obstruction, frailty, swallowing and aspiration risk, renal function and interacting medicines. Inadequate preparation invalidates surveillance assumptions and usually requires planned early repeat rather than reassurance.
Do not give generic stop dates without renal function and indication review. High-thrombotic-risk cases need specialist ownership, and every interruption requires an explicit restart plan after haemostasis.
A three-year interval after an incomplete or poorly prepared colonoscopy is false precision. First secure complete mucosal assessment and credible lesion clearance.
An early EMR site check asks whether local tissue remains; post-polypectomy surveillance asks whether future lesions arise elsewhere. They use different timing and should not be conflated.
Fragmentation prevents reliable measurement of invasion depth and margins. When cancer is plausible, en-bloc expert resection or surgical planning protects pathological decision-making.
Flat serrated lesions may be visually subtle but are premalignant. Their size and dysplasia contribute to the same high-risk algorithm rather than being dismissed as harmless hyperplastic polyps.
Preparation, sedation, bleeding and perforation burdens rise with frailty. Prevention benefit requires sufficient life expectancy and should be reconsidered rather than renewed automatically.
Assigning surveillance from the word adenoma without counting number, size, dysplasia and serrated lesions.
Fragmenting a lesion with deep-invasion features and destroying accurate cancer staging.
Placing tattoo ink immediately beneath a lesion that needs later advanced endoscopic resection.
Starting a three-year clock after poor preparation or incomplete caecal intubation.
Forgetting focused site checks after piecemeal resection of a large lesion.
Continuing surveillance indefinitely in severe frailty without revisiting benefit, burden and patient preference.
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A high-quality complete colonoscopy removes three premalignant polyps: two 4 mm tubular adenomas and one 12 mm sessile serrated lesion without cancer. Which surveillance plan matches BSG high-risk criteria?
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes
Surveillance is risk-based rather than annual by default. BSG, ACPGBI and PHE define a high-risk group after complete removal: two or more premalignant polyps including at least one advanced colorectal polyp, or five or more premalignant polyps. They receive a one-off surveillance colonoscopy at three years; people outside those criteria generally return to the appropriate national screening or symptomatic route. Local recurrence after piecemeal EMR is a different question from metachronous-cancer surveillance, so a lesion at least 20 mm needs focused early site checks before the broader interval is calculated. Always account for baseline colonoscopy quality, pathology reconciliation, hereditary phenotype, IBD, previous colorectal cancer, age, frailty and life expectancy. The best interval is useless if no one owns the booking and histology action.