[Pharmacologic Treatment of Irritable Bowel Syndrome with Predominant Constipation]

Irritable bowel syndrome with predominant constipation (IBS-C) is a functional gastrointestinal disorder characterized by abdominal pain with chronic constipation and abdominal bloating, which could significantly impair the quality of life of patients and bring substantial socio-economic burdens. Pharmacology treatment is central to managing patients with IBS-C, aiming to alleviate symptoms and improve patient treatment outcomes. Guanylate cyclase-C agonists (linaclotide and plecanatide) enhance intestinal fluid secretion and motility, normalize bowel movements, and reduce abdominal pain. Na⁺/H⁺ exchanger inhibitors (e.g., tenapanor) decrease sodium absorption, increase fluid secretion, and alleviate visceral pain. Lubiprostone activates the chloride channels to facilitate bowel movements, while polyethylene glycol laxatives regulate osmotic pressure to improve stool consistency and ease defecation. Highly selective 5-HT₄ agonists, such as prucalopride, accelerate gastrointestinal and colonic transit and improve stool frequency and consistency without increasing the cardiovascular risks raised in earlier agents such as tegaserod. Neuromodulators, including selective serotonin reuptake inhibitors and tricyclic antidepressants, help manage visceral hypersensitivity and chronic abdominal pain in selected patients. These pharmacology agents have shown efficacy and safety in clinical studies, but drug availability, adverse effects, and variable patient responses are still challenging. Effective strategies to manage IBS-C require a personalized approach, considering the patient's symptom profile, treatment goals, and safety concerns.