Introduction

Food is often reported as a trigger for symptoms in patients with irritable bowel syndrome (IBS). One of the proposed pathophysiological mechanisms is a local immune response to food antigens, triggered by a preceding infection¹.

Aims & Methods

This study aimed to investigate rectal mucosal reactions to food in patients with IBS. Therefore, patients with IBS and food-related symptoms were included. Allergies to the food items that were tested during the colonoscopic antigen provocation (COLAP) were excluded by an allergologist. The COLAP was started in the absence of macroscopic abnormalities during sigmoidoscopy. A 200 μL solution of each food antigen (wheat, gluten, soy, and milk; administered in a randomized order and blinded), a negative control (NaCl 0.9%), and a positive control (histamine) were injected in the rectal mucosa, with a positive reaction defined as mucosal edema 12 minutes after injection and judged based on a previously used semiquantitative scale ². The reaction was independently judged by two endoscopists, resulting in a positive or negative reaction when they agreed and doubtful when they did not.

Results

Data from ten patients were available for this interim analysis. Nine were female, with a median age of 45 [range 24-58] years, and a median IBS symptom severity score of 356 [range 197-416], i.e. in the moderate to severe range. Six patients had predominant constipation, one predominant diarrhea, and three mixed bowel habits. COLAP was positive in seven patients, with a positive reaction for one food antigen in three patients and for two food antigens in four patients. In the other three patients, the test was only doubtful for one of the food antigens (n=2), or negative for all (n=1). A positive reaction to gluten was observed in five patients, to soy in three, to wheat in two, and to milk in one (Table). The reaction to histamine was positive in eight patients, with no positive reaction after injection of the negative control in all.

Conclusion

A local intestinal reaction to food antigens was seen in a subset of patients with IBS. Further research will focus on underlying pathophysiological mechanisms and clinical relevance of these findings.

References

1. Aguilera-Lizarraga J, Florens MV, Viola MF, Jain P, Decraecker L, Appeltans I, et al. Local immune response to food antigens drives meal-induced abdominal pain. Nature. 2021;590(7844):151-6.
2. Bischoff SC, Mayer J, Wedemeyer J, Meier PN, Zeck-Kapp G, Wedi B, et al. Colonoscopic allergen provocation (COLAP): a new diagnostic approach for gastrointestinal food allergy. Gut. 1997;40(6):745-53.

Introduction

Ocular manifestations (OMs) are recognized extraintestinal complications in inflammatory bowel disease (IBD), but their incidence remains understudied. We aimed to evaluate the incidence and trends of OMs in a large population-based cohort of adults with newly diagnosed IBD over the past two decades.

Aims & Methods

We conducted a retrospective cohort study including all adults diagnosed with IBD between 2005 and 2024 in Maccabi Healthcare Services, Israel. Patients with prior OM diagnoses were excluded. The primary outcome was the development of OM (uveitis, episcleritis/scleritis, or orbital inflammation) following IBD diagnosis. Annual incidence trends were evaluated using the Cochran–Armitage test, and multivariable Cox models (stratified by IBD type) identified risk factors.

Results

Among 15,035 newly diagnosed IBD patients (51.8% Crohn’s disease [CD], 48.2% ulcerative colitis [UC]), 349 developed an OM over 119,669 person-years, corresponding to an incidence rate of 2.9 per 1,000 person-years (95% CI: 2.62–3.24), approximately 0.3% of IBD patients per year developed a new OM. By 5 years after IBD diagnosis, the cumulative incidence of OM was 1.7%, and by 10
years, it was 2.7%. The annual incidence rates of OM remained relatively stable from 2005 through 2024, with no clear upward or downward trend (Cochran–Armitage trend test p = 0.125, Table 1). OM incidence was higher in CD than UC (p < 0.001) and remained stable over time (p = 0.125). The median time to OM was 45 months. In CD, female sex (HR 1.62; 95% CI: 1.24–2.13) and systemic corticosteroid use (HR 1.62; 95% CI: 1.18–2.22) were associated with increased OM risk. In UC, corticosteroid use (HR 2.17; 95% CI: 1.40–3.37) and intestinal surgery (HR 3.50; 95% CI: 1.69–7.28) were significant predictors.

Table 1 – Incidence of OM among adults with IBD (2005-2024)

Conclusion

OMs in adult-onset IBD are infrequent but clinically relevant, particularly among CD patients and those with markers of severe disease. Clinician awareness and early referral remain essential for prompt diagnosis and management.