Gastrointestinal mesenchymal tumor in an 80-year-old man may cause gastrointestinal bleeding and obstructive jaundice without surgery. Gastrointestinal mesenchymal stromal tumor is the most common mesenchymal tumor in the digestive tract, its etiology is still unclear, it is currently believed that the occurrence of this disease is related to gene mutation, this disease is prevalent in the stomach, small intestine, colorectal and other parts. The clinical manifestations of the disease are different depending on the size and location of the tumor. When the tumor is small, the symptoms are not obvious, and epigastric discomfort or peptic ulcer may appear; when the tumor is large, abdominal mass can be detected. If the 80-year-old man has gastrointestinal mesothelioma without surgery, the tumor will infiltrate into the gastrointestinal lumen, which will lead to gastrointestinal bleeding phenomenon (such as vomiting blood, black stools, etc.); the tumor body increases in size, which can also lead to intestinal obstruction manifestations, such as abdominal pain, nausea, vomiting, and the anus stops defecation. Duodenal mesenchymal tumors can compress the bile ducts, thus causing obstructive jaundice (manifested as yellowing of skin and sclera, yellow urine, etc.). After an 80-year-old man is diagnosed with gastrointestinal mesenchymal tumors, it is recommended that the patient go to the hospital in a timely manner and choose the appropriate treatment after the doctor’s evaluation.