For which condition is loperamide indicated?

Loperamide is indicated for the management of diarrhea. It works by slowing down gut motility, which reduces the frequency of bowel movements and decreases the volume of diarrhea. Loperamide acts on the opioid receptors in the gut, leading to increased transit time and enhanced absorption of fluids and electrolytes from the intestinal contents.

In contrast, the other conditions listed—heartburn, constipation, and gastroesophageal reflux disease—are not treated with loperamide and require different types of medications for management. For instance, heartburn and gastroesophageal reflux disease are typically treated with antacids or proton pump inhibitors, while constipation would be managed with laxatives or lifestyle modifications. This highlights the specific role of loperamide in treating acute or chronic diarrhea, which makes it the appropriate choice in this context.