Feeling vague pain three years after stomach cancer surgery may be caused by recurrence of stomach cancer, residual gastritis, anastomotic obstruction and so on. 1. Recurrence of gastric cancer: if the patient has recurrence of gastric cancer, it can cause the symptom of stomach pain due to invasion of cancer cells. 2. Residual gastritis: if after partial gastrectomy, the residual stomach is damaged by mucous membrane due to various reasons to form gastritis, which may cause symptoms such as acidity, discomfort and pain in epigastric area. 3. Anastomotic obstruction: if the surgical anastomosis is obstructed, abdominal pain and other symptoms may occur. Regular rechecking should be done after gastric cancer surgery to prevent recurrence. If patients feel vague pain after surgery, they should go to the hospital in time to clarify the cause of the disease and carry out standardized treatment under the guidance of doctors.