OUTLINE: This is a dose escalation study of eniluracil and fluorouracil. Patients receive oral eniluracil and oral fluorouracil twice daily on days 1-21. Patients receive oxaliplatin IV over 2 hours on days 1 and 15. Treatment continues every 4 weeks in the absence of disease progression or unacceptable toxicity. Patients with complete response are treated with 2 more courses and then therapy is stopped. Cohorts of 3-6 patients receive escalating doses of eniluracil and fluorouracil until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose limiting toxicity. The recommended phase II dose (RPTD) is defined as 1 dose level below the MTD. Patients are followed at 1 month.