Pharmacotherapy for Chronic Idiopathic Constipation and Constipation-Predominant Irritable Bowel Syndrome Beyond Conventional Laxatives: A Narrative Review

Chronic idiopathic constipation (CIC) and constipation-predominant irritable bowel syndrome (IBS-C) are two highly prevalent functional gastrointestinal disorders that share overlapping features but differ in their pathophysiology and symptom profiles. Both conditions impose a significant socioeconomic burden due to their high prevalence, chronic nature, and impact on daily life. Treatment for chronic constipation begins with lifestyle modifications, including fiber supplementation, and progresses to osmotic and/or stimulant laxatives if the response is inadequate. About half of the patients treated with conventional laxatives do not respond sufficiently, which is due to multiple factors and requires additional therapy. Newer pharmacological agents for CIC and IBS-C are characterized by their targeted mechanisms, including enterokinetics, secretagogues, bile acid modulators, and sodium/hydrogen exchanger-3 inhibitors. Secretagogues like linaclotide improve both motility and sensory symptoms, which are often poorly managed by conventional laxatives. A drug-free treatment called the Vibrant capsule has been approved for CIC, enhancing peristalsis and bowel movements in patients unresponsive to traditional laxatives. Correct differentiation between CIC and IBS-C is essential, as misclassification can lead to suboptimal treatment outcomes. Future therapies are expected to better address the distinct yet overlapping features of these disorders, providing patient-specific treatment, improving symptom relief, and enhancing overall quality of life. The insights synthesized in this review may enhance our understanding of the mechanisms behind pharmacotherapy for chronic constipation and support their application in clinical practice to better patient outcomes.