Combination Chemotherapy in Treating Patients With Advanced Colorectal Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed locally advanced, locally recurrent, or metastatic colorectal adenocarcinoma not curable by surgery or radiotherapy * Histological or cytological requirement waived in patients who developed radiological or clinical evidence of metastatic cancer after a prior surgical resection unless: * More than 5 years has elapsed since primary surgery OR * Primary cancer was stage I or II * Site of primary lesion must be or have been confirmed endoscopically, radiologically, or surgically to be or have been in the large bowel * Measurable or evaluable disease * No CNS metastases or carcinomatous meningitis PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * ECOG 0-2 Life expectancy: * At least 12 weeks Hematopoietic: * Absolute granulocyte count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 9.0 g/dL (transfusion allowed) Hepatic: * Bilirubin no greater than 1.5 mg/dL * AST no greater than 5 times upper limit of normal (ULN) * Alkaline phosphatase no greater than 5 times ULN Renal: * Creatinine no greater than 1.5 times ULN Cardiovascular: * No uncontrolled hypertension * No unstable angina * No symptomatic congestive heart failure * No myocardial infarction within the past 6 months * No serious uncontrolled arrhythmia * No New York Heart Association class III or IV cardiac disease Pulmonary: * No interstitial pneumonia or extensive and symptomatic interstitial fibrosis of the lung * No pleural effusion or ascites that cause respiratory compromise (grade 2 or worse dyspnea) Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No active or uncontrolled infection * No symptomatic sensory peripheral neuropathy * No known allergy to platinum compounds * No history of gastrointestinal bleeding unless it is determined to be acceptable by the enrolling physician * No other prior or concurrent malignancy within the past 3 years except nonmelanoma skin cancer, carcinoma in situ of the uterine cervix, or other resected malignant tumor with less than a 10% probability of tumor relapse within 3 years of diagnosis * No medical or psychiatric conditions that would preclude study * No colonic or small bowel disorders with uncontrolled symptoms of more than 3 loose stools per day * Colostomy or ileostomy allowed at investigator's discretion PRIOR CONCURRENT THERAPY: Biologic therapy: * Prior adjuvant immunotherapy for resected stage II-IV disease allowed if adjuvant therapy concluded at least 1 year before documentation of recurrent disease * No concurrent sargramostim (GM-CSF) Chemotherapy: * No prior chemotherapy for advanced colorectal cancer * No prior standard adjuvant chemotherapy for rectal cancer * Prior adjuvant fluorouracil for resected stage II-IV disease allowed if adjuvant therapy concluded at least 1 year before documentation of recurrent disease Radiotherapy: * See Disease Characteristics * At least 4 weeks since prior major radiotherapy (e.g., chest or bone palliative radiotherapy) * No prior radiotherapy to more than 15% of bone marrow * No prior standard adjuvant radiotherapy for rectal cancer Surgery: * See Disease Characteristics * At least 4 weeks since prior major surgery (e.g., laparotomy) (2 weeks for minor surgery) and recovered * Insertion of a vascular access device not considered major or minor surgery Other: * No other concurrent investigational agents