A Case of Multiple Colon Ulcers due to Complications of S-1 (TS-1) / 대한소화기내시경학회지

S-1 (TS-1) is an oral anticancer drug that contains a prodrug of 5-fluorouracil. This drug exhibits high efficacy with it is used as single therapy or in combination therapy for gastrointestinal cancer, and especially advanced gastric cancer. There have not been any reports about grade 3 or 4 adverse events when using S-1. We report here on a case of multiple colon ulcers after S-1 chemotherapy in a patient with advanced gastric cancer.