Nonspecific ileitis: Impact of histopathology and gastrointestinal ultrasound in achieving the diagnosis of Crohn's disease

Abstract

Background and Aim Nonspecific ileitis is inflammation of the ileum without specific diagnostic features. A minority may go on to develop Crohn's disease, but optimal pathways of further investigation have not been established. This study aimed to identify a cohort of patients with nonspecific ileitis and to determine the value of ileal histology and gastrointestinal ultrasound in identifying/excluding Crohn's disease. Patients and Methods In a retrospective analysis, all patients having nonspecific ileitis at colonoscopy from January 2010 to August 2021 were identified. Clinical associations with those subsequently diagnosed with Crohn's disease were examined with specific reference to ileal histology and gastrointestinal ultrasound. Results Of 29 638 procedures, 147 patients (0.5%) had nonspecific ileitis. Crohn's disease was subsequently diagnosed in 8 patients (5.4%) at a median of 148 (range 27–603) days after colonoscopy. The presence of chronic inflammation on ileal biopsies was more common in those subsequently diagnosed with Crohn's disease (63% vs 20%; P = 0.0145). On gastrointestinal ultrasound, none of the 26 patients with normal bowel wall thickness (<3 mm) were subsequently diagnosed with Crohn's disease, and repeat ultrasound in 15 patients 1 year later showed no change. Of the nine patients with abnormal sonographic findings, three were diagnostic for Crohn's disease. Repeat ultrasound revealed Crohn's disease in two, while four had resolution of the abnormal findings. Conclusion Although ileal histology was of limited value in identifying patients with nonspecific ileitis who were subsequently diagnosed with Crohn's disease, gastrointestinal ultrasound was highly informative. Prospective studies are needed to confirm the value of gastrointestinal ultrasound as a diagnostic and monitoring tool in this setting.

Idiopathic terminal ileitis: myth or true entity?

“…In contrast, IDTI prevalence reported in studies including both screening and nonscreening colonoscopies was extremely variable, ranging from 0.1 to 2.2% [3,12,13]. This difference could be due to variations in the terminal ileum (TI) intubation rate, the diagnostic criteria for IDTI and the diagnostic work-up.…”

“…Noninvasive modalities (capsule endoscopy, faecal calprotectin) could be the preferred modalities to monitor these patients. Epidemiological data on IDTI derive mostly from small and heterogenous studies, and to the best of our knowledge, there is only one meta-analysis [5 & ] on IDTI (Table 1) [11][12][13][14][15][16][17][18][19][20][21]. Overall, IDTI is uncommon.…”

“…Smith et al In patients who were eventually diagnosed as Crohn's disease, the time interval is an important factor; however, the follow-up period in the many studies are fairly heterogenous. All studies reported a follow-up period of at least 2 years, except for Smith et al [13] and Mehta et al [3] who reported a median time interval of approximately 5 and 3-6 months, respectively. Figure 2 delineates the time interval between the diagnosis of IDTI and change of diagnosis to Crohn's disease, which ranged between 20 to 40 months.…”

“…While the majority of studies concentrate on the association of IDTI to Crohn's disease, others reveal diverse causes, specifically ITB in endemic regions. For instance, a recent Australian study [13] described a low progression rate of 5.4% among its 147 IDTI cohort, all of whom developed Crohn's disease within a median interval time of about 5 months. In a study on 81 patients with IDTI, Kang et al [22] reported that one developed Crohn's disease and one ITB.…”

“…Colonoscopy with histology was the only investigation performed in all patients with a change in diagnosis at follow-up, except for Sihag et al [25], in which patients were followed-up with small bowel CE. Smith et al [13] also performed small bowel ultrasound at diagnosis and follow-up. Other recent studies [7 ▪▪ ,23,25,26] included the sequential use of small bowel CE after colonoscopy, to possibly detect jejunal and proximal ileal disease, both at diagnosis and follow-up to monitor IDTI.…”