Drug used in irritable bowel syndrome with constipation
**Core Concept**
Irritable bowel syndrome with constipation (IBS-C) is a functional gastrointestinal disorder characterized by abdominal pain and changes in bowel movements, with constipation being the predominant symptom. The treatment of IBS-C involves medications that modulate gut motility, secretion, and sensation to alleviate symptoms.
**Why the Correct Answer is Right**
Lubiprostone is a chloride channel activator that increases intestinal fluid secretion, promoting bowel movements and relieving constipation in IBS-C patients. By activating the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel, lubiprostone increases the secretion of chloride and bicarbonate into the intestinal lumen, leading to increased fluid secretion and softening of stool. This mechanism helps to alleviate constipation and improve bowel habits in IBS-C patients.
**Why Each Wrong Option is Incorrect**
**Option A:** Linagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor used in the management of type 2 diabetes mellitus, which has no role in the treatment of IBS-C.
**Option B:** Metoclopramide is a dopamine antagonist that primarily acts as a prokinetic agent, increasing gastrointestinal motility and reducing nausea and vomiting, but it is not indicated for the treatment of IBS-C.
**Option C:** Alosetron is a serotonin 5-HT3 receptor antagonist used in the treatment of severe diarrhea-predominant IBS (IBS-D), but it is not used for IBS-C.
**Clinical Pearl / High-Yield Fact**
Lubiprostone is a chloride channel activator that increases intestinal fluid secretion, making it an effective treatment option for IBS-C patients who experience constipation.
**Correct Answer:** C.