Functional bowel disorders refer to disorders of gut-brain interaction that affect the intestinal tract. Irritable bowel syndrome (IBS) is the most common functional bowel disorder and affects individuals regardless of age and gender. It can result in impaired quality of life and significant health care utilization and is therefore important to recognize and manage. The diagnosis of IBS is based on clinical symptoms. IBS is categorized based on predominant bowel habit (constipation, diarrhea, mixed, or unclassified), and the treatment of IBS is individually tailored based on subtype and symptom severity.