An 82-year-old man underwent total gastrectomy(D2 lymph node dissection)in August 2006. The pathological findings indicated T4a, N3, M0, Stage IIIC gastric cancer, but adjuvant chemotherapy was not initiated. In October 2009, he presented to the hospital with dyschezia. During colonoscopy, the scope could not pass through the colon, thus indicating rectal stenosis. The biopsy findings indicated the presence of signet ring cell carcinoma, which was determined to be due to the peritoneal dissemination from the gastric cancer. To avoid the need for creating a stoma, radiation therapy(2 Gy×20; total dose, 40 Gy)and chemotherapy(weekly paclitaxel and S-1)were initiated. Rectal stenosis was improved and complete remission was maintained until May 2013.