For Prevention of Diarrhea in Patients Diagnosed With Metastatic Colorectal Cancer Treated With Chemotherapy

Inclusion Criteria: Diagnosis of colorectal cancer (either newly diagnosed or recurrent disease) with evidence of metastatic disease and present or past histological documentation of adenocarcinoma of the colon or rectum. Tumor must be measureable. Resolution of all acute toxic effects of any prior radiotherapy or surgical procedure. ECOG performance status 0 or 1. Age >= 18 years. Required baseline laboratory. Negative pregnancy test. Willingness and ability to comply with the treatment plan. Exclusion Criteria: Current enrollment in another clinical trial. Prior adjuvant therapy for colorectal cancer <= 6 months prior to randomization. Prior systemic anticancer therapy or intra-arterial cytotoxic chemotherapy given as treatment for metastatic colorectal cancer. Known allergy to CPT-11, 5-FU, LV, celecoxib, other COX-2 inhibitors, non-steroidal anti-inflammatory drugs (NSAIDS), salicylates, or sulfonamides. Chronic concomitant use of full-dose aspirin, other NSAIDs or other COX-2 inhibitors for a chronic nonmalignant condition. A requirement for chronic concomitant use of low-dose (cardioprotective) aspirin. Chronic oral steroid use for treatment of a non-malignant condition. Known ulceration of the gastric or duodenal mucosa <= 30 days prior to randomization. Need for concomitant fluconazole or lithium. Any known significant bleeding disorder. Active inflammatory bowel disease or chronic diarrhea.