This randomized phase III trial is studying giving irinotecan and cetuximab together with bevacizumab to see how well it works compared with giving irinotecan and cetuximab alone in treating patients with metastatic colorectal cancer that progressed during first-line therapy. Drugs used in chemotherapy, such as irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as cetuximab and bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Bevacizumab may also stop the growth of tumor cells by blocking blood flow to the tumor. It is not yet known whether irinotecan and cetuximab are more effective with or without bevacizumab in treating metastatic colorectal cancer.