Gastrointestinal mesenchymal tumors are common mesenchymal tumors of the gastrointestinal tract, originating from Cajal mesenchymal cells, and can occur throughout the gastrointestinal tract, most commonly in the stomach and small intestine, but also outside the gastrointestinal tract, the omentum, and the mesentery. Gastrointestinal mesenchymal tumors outside of the stomach are those that occur in areas of the GI tract other than the stomach, such as the small intestine, colon, and rectum. Gastrointestinal mesothelioma occurs most frequently in the stomach (about 60% to 70% of cases), followed by the small intestine (20% to 30%), and can also occur in the colon and rectum (about 5% of cases). It can also occur outside the gastrointestinal tract, but only with less probability. Therefore, no matter which part of the gastrointestinal tract it occurs in, it is necessary to seriously do the corresponding examinations such as pathological biopsy, immunohistochemical examination, actively cooperate with the doctor’s treatment, regular follow-up, take medication on time, and maintain a healthy life habit.