Cracks in the tongue of patients with bile reflux may be caused by irritation of the oral mucosa due to reflux of bile into the mouth, or it may be due to dysbiosis caused by indigestion. Bile reflux is a manifestation of gastroesophageal reflux disease (GERD), which is mainly caused by impaired anti-reflux structure and function of the esophagus or reduced clearance capacity. Bile is a strong alkaline substance, and when bile refluxes into the oral cavity, it irritates the oral mucosa, leading to keratinization defects and cracks in the epithelial cells of the oral mucosa. In addition, patients with GERD are usually accompanied by abnormal digestive function and dyspepsia, which causes food to accumulate in the gastrointestinal tract, leading to the growth of harmful bacteria in the gastrointestinal tract and the decomposition of food to produce toxic substances, which can irritate the oral mucosa and salivary glands, resulting in cracks on the tongue. Patients with bile reflux are advised to seek prompt medical attention and receive active treatment to avoid delays.