P149 Prioritising colonoscopy by faecal immunochemical test result does not delay the diagnosis of inflammatory bowel disease

White, K.(1);Makin, A.(1);

(1)Manchester University NHS Foundation Trust, Gastroenterology, Manchester, United Kingdom;

Background

Due to the Covid-19 pandemic there has been unprecedented pressure on endoscopy services. Faecal immunochemical tests (FIT) are designed to detect small amounts of blood in stool samples using antibodies specific to human haemoglobin. This test is highly specific and sensitive for colorectal cancer (CRC) and has been shown to detect mucosal healing in ulcerative colitis(1).  FIT was utilised at our hospital to prioritise urgency of colonoscopy referrals. We aimed to determine whether this caused a delay in the diagnosis of inflammatory bowel disease (IBD) in this cohort.

Methods

Consecutive colonoscopy referrals (urgent, semi-urgent and routine) from September 2020 to April 2021 were prioritised by FIT result. Any patient with a FIT>/=10mcg were deemed category 1 (colonoscopy within 30 days) and FIT<10mcg were deemed category 2 (colonoscopy within 90 days). Demographic data were collected along with procedure result and histology.

Results

One hundred and twelve patients (52% female) had a FIT test and a subsequent diagnostic test (96 had a colonoscopy, 12 had a flexible sigmoidoscopy, 3 had a CT colonography and 1 patient declined a colonoscopy but later had a CT abdomen and pelvis. Patients who did not go on to have a diagnostic test were excluded. Sixty four patients had a FIT<10 (mean age 61), 35 had a FIT 10-400 (mean age 64) and 13 patients had a FIT>400 (mean age 52).

Median number of days from FIT result to diagnostic test was 56 (range -9-163) in the group with FIT<10, 44 (-28-93) in the group with FIT 10-400 and 44 (10-89) in the group with FIT>400.

There were no cancer diagnoses in the FIT<10 group. No patients in this group had colonic inflammation. Of the patients with FIT 10-400; 4 had colonic or ileocaecal valve inflammation, 12 had polyps and 2 had a CRC. Of the patients with inflammation one had mild right sided inflammation (FIT 228), one had colitis (FIT 367), one had proctitis (FIT 87) and one had ileitis of the ileocaecal valve (FIT 119).

Of the patients with FIT>400; 4/13 had a colorectal malignancy (one of which was a polyp cancer), 4/13 had colonic polyps and 3/13 had active colonic inflammation. Of the patients with inflammation one had right sided inflammation, likely crohns disease, one had severely active ulcerative colitis (UC) and one had mild proctitis, likely UC.

Conclusion

In this cohort there were no CRC or IBD diagnoses in the patients with FIT<10. Therefore there was no delay in investigation of any patient subsequently diagnosed with IBD. This suggests that FIT may be safely used to stratify the priority of referrals for colonoscopy in symptomatic patients. Further work is required to confirm this.