Background: Chronic abdominal pain is prevalent in individuals with inflammatory bowel diseases (IBD). However, the determinants and phenotypes of IBD-associated pain are not well-characterized, frustrating effective pain management and mitigation strategies.

Aims: This is an ongoing descriptive, cross-sectional study aimed at phenotyping the types of pain experienced by patients with IBD, the impact on health-related quality of life (HRQoL) and psychological health, and relationship to disease activity assessed by clinical metrics and endoscopy.

Methods: Fifty-eight adult patients diagnosed with IBD were prospectively enrolled at a single academic medical center between October 17, 2022 and November 7, 2023. Patients completed a set of online patient-reported outcome measures (PROM)-based standardized and validated questionnaires (Table 2) just prior to a scheduled colonoscopy. Endoscopically active disease was defined as Mayo Endoscopic Score ≥ 1 for ulcerative colitis (UC) and SES-CD ≥ 3 for Crohn’s Disease.

Results: A total of 58 patients (28 UC/30 Crohn’s, 24 male/34 female, median age 44.5±14.5 years) were included. An initial analysis examined relationships based on endoscopic disease activity. Interestingly, there was no significant difference between those with endoscopically active disease and those without on metrics of pain, HRQoL, or impact on psychological health (p>0.05). However, those with endoscopically inactive disease had significantly higher scores on central sensitization (CS) (31.1±11.5 vs. 23±12.1, p<0.05). Using a validated score threshold of 40 on the central sensitization inventory (CSI), the cohort was then stratified into two new groups (those with and without evidence of CS). Overall, 12/58 patients met diagnostic criteria for CS. Table 1 summarizes the baseline characteristics of the two groups. As detailed in Table 2, those with CS had higher scores on abdominal pain (severity and interference, including catastrophizing), visceral hypersensitivity, lower scores on HRQoL questionnaires, and greater scores on depression and anxiety scales (p<0.05). There was no significant difference in neuropathic pain (p=0.85).

Conclusion: Central sensitization affected at least 20% of this cohort of IBD patients, which is consistent with prior studies. Interestingly, there was a trend towards more central sensitization in those with quiescent disease. CS was associated with worse pain, HRQoL, and psychosocial distress across a broad range of outcomes measured. These data support enhanced attention to contribution of CS to pain in IBD patients, particularly those with persistent pain in remission, as therapies emerge for the treatment of CS.

Table 1. Baseline characteristics of IBD patients meeting criteria versus patients not meeting criteria for central sensitization

Table 2. Questionnaire results of IBD patients meeting criteria versus patients not meeting criteria for central sensitization

Robert Burns

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