Chemotherapy With Raltitrexed and Fluorouracil 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 trial to study the effectiveness of raltitrexed and fluorouracil in treating patients who have colorectal cancer that is metastatic, recurrent, or cannot be surgically removed.