Resolution of Long-Standing Irritable Bowel Syndrome Symptoms After Treatment of Psoriasis With Risankizumab.

Psoriasis is a chronic immune-mediated inflammatory disease associated with systemic comorbidities, including gastrointestinal disorders. Emerging evidence supports a bidirectional gut-skin axis, with shared immunologic pathways involving the interleukin (IL)-23/IL-17 axis. Irritable bowel syndrome (IBS), traditionally considered a functional disorder, has also been linked to low-grade inflammation and cytokine dysregulation. We report a case of a 67-year-old man with moderate plaque and inverse psoriasis and longstanding IBS with diarrhea (IBS-D) who experienced complete resolution of gastrointestinal symptoms following treatment with risankizumab, an IL-23 inhibitor. Improvement in IBS symptoms began within weeks of therapy initiation and was sustained at follow-up, alongside complete skin clearance. No other changes in medications or lifestyle were identified. This case highlights a potential role of IL-23-mediated inflammation in IBS pathophysiology and suggests that targeted inhibition of the IL-23/IL-17 axis may benefit select patients with concurrent dermatologic and gastrointestinal disease.