Decoding Abdominal Pain in Constipation-predominant Irritable Bowel Syndrome and Functional Constipation: Mechanisms...

Abdominal pain in constipation-predominant irritable bowel syndrome (IBS-C) and functional constipation (FC) remains a difficult clinical challenge due to unclear pathophysiological mechanisms and limited pain-targeted treatments. This review critically evaluates the evidence on the underlying pain mechanisms in IBS-C and/or FC and explores management strategies, their limitations, and future directions.

Most research on constipation-related pain is based on IBS-C patients or animal models, with limited studies focusing on FC. Visceral hypersensitivity, serotonin dysregulation, gut-brain axis dysfunction, and central/peripheral nervous system alterations are implicated in IBS-C pain, while FC pain is less studied and may be primarily linked to colonic distension and motility dysfunction. Management strategies include 5-HT4 agonists, GC-C agonists, chloride channel activators, psychological therapies, probiotics and complementary medicine. Despite available treatment options, managing abdominal pain in IBS-C and FC remains challenging due to heterogeneous pathophysiology and limited targeted therapies. While some interventions provide symptomatic relief, there is no universally effective treatment for abdominal pain across all patients. Future research should focus on identifying pain-specific biomarkers, refining diagnostic criteria, and integrating multi-omics data and neuroimaging techniques to better distinguish pain mechanisms in IBS-C versus FC and develop more precise, patient-centered interventions.