DISEASE CHARACTERISTICS: Histologically or cytologically confirmed metastatic adenocarcinoma of the colon or rectum that is not amenable to potentially curative therapy (e.g., inoperable metastatic disease) At least 1 unidimensionally measurable lesion at least 20 mm in diameter by conventional CT or MRI scan or at least 10 mm in diameter by spiral CT scan Progressive disease by CT or MRI scan during or no more than 6 months after the last dose of prior first-line irinotecan, fluorouracil, and leucovorin calcium (Saltz regimen) for metastatic disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 50-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) AST and ALT no greater than 2 times ULN (no greater than 5 times ULN if liver metastases present) Alkaline phosphatase no greater than 2 times ULN (no greater than 3 times ULN if liver metastases present) Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No uncontrolled high blood pressure No unstable angina, symptomatic congestive heart failure, or serious cardiac arrhythmia No New York Heart Association class III or IV heart disease No history of cardiac toxicities with prior fluorouracil and leucovorin calcium No myocardial infarction within the past 6 months Pulmonary: No interstitial pneumonia or extensive and symptomatic fibrosis of the lung Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study No known dihydropyrimidine dehydrogenase deficiency No allergy to platinum-containing drugs No history of intolerance to study anti-emetics (e.g., 5-HT3 antagonists) No known peripheral neuropathy (absence of deep tendon reflexes as sole deficiency allowed) No uncontrolled diabetes No active infection No other active malignancy originating from primary site other than colon or rectum

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics One and only 1 prior chemotherapy regimen for metastatic disease consisting of first-line irinotecan, fluorouracil, and leucovorin calcium (Saltz regimen) Prior adjuvant fluorouracil with leucovorin calcium allowed At least 3 weeks since prior chemotherapy for metastatic disease and recovered No prior adjuvant irinotecan No prior oxaliplatin Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to study lesions unless evidence of progressive disease within the radiotherapy port At least 3 weeks since prior radiotherapy Surgery: See Disease Characteristics At least 4 weeks since prior major surgery and recovered Prior surgical resection of primary tumor or metastases allowed Other: At least 30 days since prior investigational drugs No other concurrent investigational agents No other concurrent anti-cancer therapy No concurrent participation in other investigational trials