Irritable bowel syndrome is the most common chronic functional gastrointestinal disorder that is characterised by abdominal pain associated with defecation, accompanied by a change in the frequency of bowel movements or stool form. Although it has a significant impact on a patient’s quality of life, it is not a terminal illness. Lately, there has been an increasing interest in nutritional treatment for irritable bowel syndrome, especially a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP). These carbohydrates ferment easily, they are poorly absorbed and have high osmotic pressure whereby they can trigger gastrointestinal disturbances in patients with irritable bowel syndrome. Many studies demonstrated that FODMAP restriction reduces the osmotic load and gas production in the small intestine and the colon, ensuring symptomatic relief in patients suffering from irritable bowel syndrome. Long-term health effects of using a low-FODMAP diet are not known, therefore, stringent FODMAP restriction is not recommended because of risks of inadequate nutrient intake and potential harmful effects from altered gut microbiota. In summary, there is evidence to strongly support the efficacy of a low-FODMAP diet in the treatment of irritable bowel syndrome. However, further and more detailed studies are required to understand any potential side effects of long-term restriction of FODMAP.