Fruquintinib, as a standard treatment for refractory metastatic colorectal cancer (mCRC), has attracted increasing research efforts to explore its innovative strategies in combination with immunotherapy and chemotherapy because of its multi-target mechanism which enhances the sensitivity of the immune system and chemotherapy, aiming to further improve the survival benefits for mCRC patients. Trifluridine/tipiracil (TAS-102) is also a standard treatment for mCRC. This study aims to investigate the safety and effectiveness of the combined use of these two drugs in mCRC.