INTRODUCTION: Measurement of gastrointestinal (GI) transit is increasingly becoming a valuable tool in understanding the pathophysiology of symptoms of many digestive diseases, including irritable bowel syndrome (IBS). The objective of this article is to review the relevance of GI transit abnormalities for symptoms of IBS. These abnormalities relate to gastric emptying, small bowel transit, and colonic transit (whole gut transit). AREAS COVERED: The article briefly describes the current methods of assessment, factors that influence the result of these methods and the relationship of abnormalities of GI transit with symptoms that have been reported in IBS patients. Finally, a recommendation to guide the application of transit studies in IBS in both clinical practice and research is provided. EXPERT OPINION: Gastrointestinal transit is relevant to symptoms of bowel habits (stool frequency and form) and the relevance for other GI symptoms in IBS is not straightforward and needs further characterization. Intervention studies in IBS that incorporate objective measures of gut transit alongside symptom evaluation are warranted. Incorporating artificial intelligence into the methods of measuring transit could improve accuracy and simplify the measurements.