Ricerc@Sapienza

Background: Colorectal polyps are reported in 6,1% of paediatric colonoscopies and in 12% of those performed for
lower gastrointestinal bleeding. Although colonoscopy is widely used in paediatric patients, it requires bowel
preparation and general anaesthesia or deep sedation, and in rare cases, it can cause complications. Non-invasive
screening techniques able to predict polyps in children with isolated and sporadic rectal bleeding may play a key
role in the selection of patients needing colonoscopy.
Methods: We enrolled all children undergoing colonoscopy for isolated and sporadic rectal bleeding to determine
the diagnostic accuracy of faecal calprotectin, ultrasonography (US) and digital rectal examination as diagnostic
methods for screening colorectal polyps.
Results: A total of 26 of 59 enrolled patients (44.1%) had colonic polyps, one patient had multiple polyps, and 23%
of children had polyps proximal to the splenic flexure. The diagnostic accuracy of faecal calprotectin for detecting
colorectal polyps was 96.6%, with a sensitivity of 100%. False-positive faecal calprotectin was shown in 2 patients
with non-steroidal anti-inflammatory drug-related lesions. The diagnostic accuracy of ultrasound was 77.9%. Polyps
not seen with ultrasound tended to be relatively smaller (1.5 vs 2.3, p = 0.001) and located in the rectum. The
combined use of FC, US and digital rectal examination obtained a specificity and PPV of 100%.
Conclusions: FC combined with US and digital rectal examination is a good and promising non-invasive screening
test for detecting colorectal polyps in children with isolated and sporadic rectal bleeding.