Chemotherapy in Treating Patients With Recurrent or Metastatic 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 II trial to study the effectiveness of trimetrexate glucuronate, fluorouracil, and leucovorin in treating patients with recurrent or metastatic colorectal cancer.