A Narrative Review of Irritable Bowel Syndrome with Diarrhea: A Primer for Primary Care Providers

Irritable bowel syndrome with diarrhea (IBS-D) is a chronic disorder of gut–brain interaction, characterized by recurrent abdominal pain in association with more frequent, loose stools. The pathophysiology of irritable bowel syndrome (IBS) includes disordered gut motility, alterations in gut microbiota, neural-hormonal system abnormalities, immune reactivity, and visceral hypersensitivity. Timely diagnosis of IBS-D can be achieved easily using clinical criteria. Formal IBS diagnosis is important for optimizing treatment and patient outcomes and facilitating patient access to appropriate educational resources. Yet, given the symptom overlap with other gastrointestinal conditions, diagnosis of IBS-D often is perceived to be challenging. Treatment of IBS includes both nonpharmacologic and pharmacologic options. Rifaximin, alosetron, and eluxadoline are effective treatments indicated for IBS-D, but have limited availability internationally. Dietary approaches may also be indicated for certain patients with IBS-D. Psychological interventions may be effective in treating abdominal pain alone and global symptoms in IBS. We describe use of these diverse therapies and provide an overview to facilitate the primary care provider’s approach to distinguishing IBS-D from other conditions with symptom overlap.