Background The association of autoimmune liver disease (AILD) and inflammatory bowel disease (IBD) is well documented. IBD affects about 45% of children with autoimmune sclerosing cholangitis (AISC) and about 20% of those with autoimmune hepatitis (AIH). The aim of this study was to describe the clinical features of AILD associated with IBD and to evaluate the role of fecal calprotectin and the time to look for IBD in patients with primary diagnosis of AILD.

Methods We have conducted a retrospective review of paediatric patients with primary diagnosis of AILD and IBD between 2010 and 2018. Patients who were referred or diagnosed with IBD first were excluded. Diagnosis of IBD was based on clinical history, endoscopic appearance and histology findings. AILD patients were classified to AIH or AISC according to histology, radiology results and circulating antibodies. Patients’ demographics, symptoms, FC, blood tests, timing before IBD diagnosis and treatment were collected.

Results 114 patients with AILD were identified: 74 (64%) had screening with FC, 48/74 (64%) had abnormal and 26 (35%) normal test. 67% of FC performed at the diagnosis of liver disease. 48 patients had at least one endoscopy, 25(52%) were diagnosed with IBD, 8 patients had normal endoscopy but positive FC of mean value 162, (range 60–332). 15 had no endoscopy despite abnormal FC. 6/26 patients with normal FC underwent endoscopy which was normal. Reason was persistently elevated liver enzymes, relapse of AILD or ongoing bowel symptoms. 25/114 (21%) patients were diagnosed with IBD, 14/25 (56%) had AISC, the rest AIH. 25% had family history of autoimmunity. Mean FC at diagnosis of IBD was 646 (range 60–4004). 14 were males and the mean age at diagnosis was 10 years. 18/25 (78%) had ulcerative colitis (UC), 2/25 (0.8%) Crohn’s disease and 5/25 (2%) indeterminate colitis(IBDU). 12/14 patients with AISC had UC and 2 IBDU. 40% of patients had simultaneous diagnosis of AILD and IBD, all presented with symptoms of bowel disease and abnormal GGT and/or aminotransferase activity (6/10 had PR bleeding). 15 (60%) patients were diagnosed with AILD and concomitant IBD after 19 months (mean time). In 7/15 gut symptoms improved since immunomodulators started but FC was raised, 3/15 had no gut symptoms but raised FC on screening and 5/15 developed bowel symptoms after liver diagnosis, in 3 of them FC was raised since liver diagnosis. Endoscopic features included pancolitis in 60% and ileitis in 20%. Histological features were more consistent with those of mild to moderate UC (78%). All patients diagnosed with AILD were started on steroids, 9/25 were already on Azathioprine before the endoscopic assessment for IBD.

Conclusions 20% of patients with primary diagnosis of AILD had IBD. 40% had simultaneous diagnosis; all had raised FC since AILD was identified. We recommend FC routinely in children with AILD for the early diagnosis of IBD. Colonoscopy should be considered in patients with symptoms of IBD and the ones with clearly elevated FC. The timing of the assessment is of paramount as immunosuppresive treatment can mask symptoms and change the disease activity.