 This randomized phase II trial studies how giving a drug called levocetirizine to patients with colorectal cancer affects their tumor response to capecitabine and bevacizumab. Capecitabine is a chemotherapy drug that blocks tumor growth by disrupting DNA and RNA synthesis and repair cell division and survival. Bevacizumab is a monoclonal antibody that blocks the ability of tumors to grow and spread by inhibiting the growth of blood vessels that feed them. Patients with colorectal cancer can develop a resistance to the effects of bevacizumab. Levocetirizine may decrease tumor resistance to bevacizumab. Giving bevacizumab, capecitabine, and levocetirizine dihydrochloride together may be an effective treatment for refractory colorectal cancer. 