In this study, we demonstrated the efficacy and safety of FOLFIRI plus bevacizumab regimen with an initial irinotecan dose of 180 mg/m2 in patients with advanced or recurrent colorectal cancer who discontinued first-line oxaliplatin-based regimen and who were of the wild-type or heterozygous group for UGT1A1 polymorphisms. Here, UGT1A1 is linked to colorectal cancer.