Cholecystectomy is a common surgical gold-standard treatment for cholelithiasis and its complications. Generally, gallbladder removal has no long-term ramifications, and most patients recover quickly without impairment on daily living activities. Nonetheless, some patients are found to develop postcholecystectomy syndrome (PCS) or diarrhoea (PCD), which can be uncomfortable, inconvenient and impair living quality. There is neither clear aetiology, nor clear solution for PCS/PCD. The significance of gut microbiome in maintaining a healthy gastrointestinal system is well-established. Dysbiosis, an imbalance between commensal and pathogenic bacteria, can lead to multiple GIT disorders like IBS or functional dyspepsia and has a strong association with change in stool consistency [1-3]. Alteration in gut microbiota can easily occur with physical or chemical changes. An invasive procedure like cholecystectomy exposes the intestinal lumen to exogenous bacteria and causes inflammatory changes, while secretory pattern changes of bacteriostatic bile acid disrupt the pH and microbial composition of the intestinal lumen. As such, it is worth understanding GIT microbiota changes post-cholecystectomy. While the concept of gut microbiome changes potentially causing PCS/PCD is not unknown, there is lack of literature reviewing research on what these microbial alterations are and establishing their association with PCS/PCD. In this review, we consolidate previous findings on post-cholecystectomy microbial alterations, effectiveness of diet on PCS/PCD based on gut microbiota and discuss the overall link between gut microbiome and PCS/PCD. This can deepen insight into aetiologies of idiopathic PCS/PCD, provide better management of PCS/PCD-associated comorbidities, and potentially offer a resolution for PCS/PCD through prescription of probiotics and prebiotics.