Utility of the Inflammatory Bowel Disease Serology, Genetics, and Inflammation (IBD-SGI) Panel in the Evaluation of Atypical Ulcerative Colitis With Active Nonsteroidal Anti-Inflammatory Drug Use: A Case Report.

Hematochezia has a broad differential, including nonsteroidal anti-inflammatory drug (NSAID)-induced, infectious, and inflammatory colitis. Colonoscopy with biopsy is primarily used to evaluate suspected colitis or inflammatory bowel disease (IBD) in patients with hematochezia, rather than to diagnose all causes of hematochezia. While the inflammatory bowel disease serology, genetics, and inflammation (IBD-SGI) blood panel test has been studied and marketed by laboratories, it is not widely implemented in routine clinical practice due to the restriction of current clinical guidelines, lack of FDA clearance/approval, and limited medical insurance coverage. Thus, we report a case of the utility of the IBD-SGI panel in the evaluation of atypical ulcerative colitis (UC) with active NSAID use. A 39-year-old man with hematochezia, diarrhea, and chronic high-dose NSAID use developed anemia, elevated fecal calprotectin, and endoscopic evidence of inflammation. Biopsies by colonoscopy showed focal colitis with features suggestive of both NSAID injury and IBD. To provide additional diagnostic support in this challenging case, an IBD-SGI blood panel was used. When interpreted with the patient's clinical presentation, elevated fecal calprotectin level, colonoscopic findings, and histopathologic features, the panel results supported a diagnosis of UC. Based on the overall clinic-pathological assessment, including continuous circumferential inflammation on colonoscopy and histopathologic evidence of chronic IBD, the patient was diagnosed with UC and treatment with vedolizumab was initiated. Anemia attributed to hematochezia was also managed. At the three-month follow-up, the patient had resumed his daily activities and returned to work. In the setting of overlapping features of UC and possible NSAID-associated colitis, the IBD-SGI panel provided adjunctive diagnostic information. This case highlights the panel's potential value as a supportive tool when endoscopic biopsy findings are inconclusive and multiple possible etiologies coexist.