Eniluracil, Fluorouracil, and Oxaliplatin in Treating Patients With Advanced Colorectal Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.
PURPOSE: Phase I/II trial to study the effectiveness of combining eniluracil, fluorouracil, and oxaliplatin in treating patients who have advanced colorectal cancer that has been treated previously.