Colonic polyps removal: methods, procedures and what to expect
Colonic polyps are commonly identified during bowel investigations, particularly colonoscopy, and whilst many are benign, some have the potential to progress to bowel cancer over time.
In this article, consultant gastroenterologist Dr Jonathan Landy based at Cleveland Clinic London Hospital explains what colonic polyps are, why removal is recommended, and the range of modern techniques used to remove them safely and effectively.
What are colonic polyps?
Colonic polyps are small growths that develop on the inner lining of the colon or rectum. They vary in size, shape and histological type. Most are non-cancerous, but certain types, particularly adenomatous polyps, carry a risk of malignant transformation if left untreated.
Polyps are often discovered during routine screening colonoscopy or investigations for symptoms such as rectal bleeding, iron-deficiency anaemia, or changes in bowel habit.
Why removal is recommended
The primary aim of removing colonic polyps is prevention of bowel cancer. Polyp removal reduces long-term cancer risk and allows histological examination to determine the type of polyp and whether further surveillance colonoscopy is required.
Colonoscopic polypectomy: the main approach
Most polyps are removed during colonoscopy, a procedure in which a flexible camera examines the large bowel.
Cold snare polypectomy
This technique is commonly used for smaller polyps. A wire loop is used to mechanically remove the polyp without electrical current. It is safe, efficient, and associated with a low risk of complications such as bleeding.
Hot snare polypectomy
Larger polyps are often removed using a snare combined with diathermy (electrical current). This allows simultaneous cutting and cauterisation, reducing bleeding risk and improving completeness of resection.
Biopsy forceps removal
Very small polyps may be removed using biopsy forceps. This method is typically reserved for diminutive lesions and is quick and straightforward.
Advanced endoscopic techniques
For larger or more complex lesions, specialist techniques may be required.
Endoscopic mucosal resection (EMR)
EMR involves injecting fluid beneath the polyp to lift it away from deeper layers of the bowel wall, allowing safe removal, often in sections. It is widely used for flat or broad-based polyps.
Endoscopic submucosal dissection (ESD)
ESD is a highly specialised technique used for larger or potentially pre-cancerous lesions. It enables en-bloc removal (in one piece), allowing precise histological assessment. It requires significant expertise and is usually performed in specialist centres.
Surgical removal
In a minority of cases, endoscopic removal is not suitable. This may occur if a polyp is very large, inaccessible, or suspicious for cancer. In such cases, surgical resection of part of the colon (colectomy) may be recommended, often using minimally invasive (keyhole) techniques.
After polyp removal and follow-up
All removed colonic polyps are sent for histological analysis. The results determine whether further treatment or surveillance colonoscopy is required. Follow-up intervals depend on polyp type, size, number, and pathology results.
Removal of colonic polyps is a well-established and highly effective method of preventing bowel cancer. With a range of endoscopic and surgical options available, treatment can be tailored to the size, type, and complexity of each polyp.