IBD Curriculum Topic 8.3, 8.4, 8.5
Perform a screening colonoscopy 6-8 years after symptom onset in those with Crohn’s Disease. Thereafter, some national organisations recommend interval surveillance based on the most recent colonoscopy and risk stratification as follows:
Future surveillance not indicated:
- Absence of colonic inflammation
5-yearly colonoscopy:
- Colitis affecting less than 50% of the colon surface area
- Extensive colitis with mild endoscopic or histological active inflammation
3-yearly colonoscopy:
- Post-inflammatory polyps
- Colorectal cancer in a first-degree relative older than 50 years
- Extensive colitis with moderate or severe endoscopic or histological inflammation
Annual colonoscopy:
- Stricture within the past 5 years
- Dysplasia within the past 5 years in a patient who declines surgery
- PSC (including post-orthotopic liver transplant) from time of diagnosis of PSC
- Colorectal cancer in a first-degree relative younger than 50 years
Pan-colonic dye spray (e.g. 0.1% indigo-carmine solution) should be used, with targeted biopsy of abnormal areas. If dye is not used, take 2-4 random biopsies from every 10 cm of the colon.
- Colectomy is not necessary if a dysplastic polyp can be entirely removed endoscopically, in the absence of dysplasia in the surrounding tissues.
- There is little evidence for pouch surveillance. Perform surveillance every 5 years. Consider annual surveillance in those with:
- previous dysplasia or colorectal cancer
- PSC
- Type C pouch mucosa (permanent, persistent atrophy and severe inflammation)
IBD Curriculum Topic 8.3, 8.4, 8.5
- Longstanding colitis increases the risk of developing colon cancer.
- Population based studies have shown that this is less than previously thought, and mainly limited to sub-groups (e.g. onset before adulthood; duration> 10y; concomitant PSC).
- Histologic or macroscopic pancolitis carries the highest risk, with no increased risk for patients with proctitis.
- Disease activity, post-inflammatory polyps and possibly a family history of CRC are additional risk factors.
- Surveillance colonoscopies may detect CRC earlier, and although this may improve prognosis it has not been definitely proven to do so.
- Colonoscopy can be considered in all patients with at least distal colitis 8 years following symptom onset, but annually at any time point following diagnosis of PSC.
5-yearly colonoscopy:
- Colitis affecting less than 50% of the colon surface area
- Extensive colitis with mild endoscopic or histological active inflammation
3-yearly colonoscopy:
- Post-inflammatory polyps
- Colorectal cancer in a first-degree relative older than 50 years
- Extensive colitis with moderate or severe endoscopic or histological inflammation
Annual colonoscopy:
- Stricture within the past 5 years
- Dysplasia within the past 5 years in a patient who declines surgery
- PSC (including post-orthotopic liver transplant) from time of diagnosis of PSC
- Colorectal cancer in a first-degree relative younger than 50 years
A rectal remnant still requires standard-interval surveillance. The procedure should be performed when the disease is in remission. Procedures need repeating with poor bowel preparation.
Pan-colonic chromoendoscopy (e.g. 0.1% indigo-carmine solution) should be undertaken, with targeted biopsies of any lesion and 2 biopsies taken each 10 cm to assess disease activity and extent. If only white light colonoscopy is performed, 4 biopsies should be taken every 10 cm although this is clearly an inferior surveillance strategy. Polypectomy depends on type of lesion.