A 77-year-old man underwent surgery for sigmoid colon cancer. He was diagnosed with Stage IIIa colon cancer; there- fore, we initiated oral administration of adjuvant chemotherapy comprising uracil/tegafur(UFT)plus Leucovorin(LV). However, chemotherapy was stopped after 21 days because of fatigue and diarrhea. He recovered after 3 weeks, and we administered the same regimen with a dose reduction. However, he again experienced fatigue and diarrhea after 20 days; therefore, chemotherapy was discontinued. Subsequently, he was hospitalized 8 times for conditions such as diarrhea, hypoalbuminemia, and fever. Computed tomography revealed thickening of the transverse colonic wall and colonoscopy revealed colitis, which we believe was induced by UFT plus LV. Twelve months after the last chemotherapy session, he was diagnosed with Clostridium difficile colitis. Therefore, we initiated the oral administration of vancomycin, which resulted in rapid recovery from colitis. However, he developed liver metastasis and died 29 months after the initiation of chemotherapy. We believe that this severe case of intractable colitis was caused by UFT plus LV. Therefore, we report this case with a review of the literature on enteritis induced by fluorouracil-based anticancer agents in Japan.