More than eight months after the surgery of small intestinal mesenchymal stromal tumor, the small intestinal resection pain bleeding after defecation may be caused by intestinal inflammation and infection or constipation and other reasons. 1. Inflammatory bowel infection: bleeding after bowel resection after small bowel mesothelioma surgery may be caused by prolonged inattention to dietary hygiene and bacterial or viral infection, resulting in inflammatory bowel infection. 2. Constipation: if you often eat some stimulating or indigestible food in your life, you may have constipation, and the dryness of stool during defecation will lead to the damage of anal opening, which will cause the bleeding of anal opening after defecation. When bleeding after defecation, it is recommended to go to the gastroenterology department or general surgery department of the hospital as soon as possible, anorectal examination, to clarify the cause of the disease, and then follow the doctor’s instructions for treatment.