<p>Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are distinct gastrointestinal conditions, but they frequently share overlapping clinical symptoms such as abdominal pain, bloating, and altered bowel habits. IBD is defined by the presence of chronic immune-mediated inflammation, and IBS is characterized by gastrointestinal symptoms in the absence of endoscopic and histologic inflammation. When patients with IBD continue to experience IBS-like symptoms despite remission of inflammation, this phenomenon is commonly referred to as IBD-IBS overlap. These patients pose diagnostic and therapeutic challenges, as symptom persistence may reflect lingering immune activation, disrupted barrier function, visceral hypersensitivity, gut-brain axis dysfunction, or microbiome alterations. This review synthesizes emerging evidence on the shared mechanisms underlying IBD and IBS and outlines a multimodal treatment approach that includes pharmacologic management, dietary interventions, mind–body therapies, and microbiome-directed strategies such as probiotics and fecal microbiota transplantation.</p>