Inclusion Criteria:

- Histologically confirmed metastatic adenocarcinoma of the colon or rectum for which
no further standard chemotherapy is considered to be effective. Patients must have
failed 5-FU, CPT-11 and/or oxaliplatin based chemotherapy.

- SWOG performance status 0-1

- ANC>1000, platelets >100,000.

- Total bilirubin < 2 x upper limit of normal. Transaminase (AST and/or ALT) < 2 x
upper limit of normal or < 5 x upper limit of normal in patients with liver
metastasis.

- Serum creatinine < 1.25 x institutional upper limit of normal.

- Female patients of child-bearing potential must have negative pregnancy test within 7
days before initiation of study drug dosing.

Exclusion Criteria:

- Patient has received any other investigational agent within 28 days of first day of
study drug dosing.

- History of another malignancy within 3 years prior to study entry, except curatively
treated non-melanoma skin cancer, prostate cancer, or cervical cancer in situ.

- Patient has another severe and/or life-threatening medical disease.

- Patient has an acute or known chronic liver or kidney disease (e.g., chronic active
hepatitis, cirrhosis, chronic renal insufficiency).

- Patient has a known diagnosis of human immunodeficiency virus (HIV) infection.

- Patient has received chemotherapy within 4 weeks (6 weeks for nitrosourea,
mitomycin-C or any antibody therapy)

- Patients with symptomatic brain metastasis.

- Patient with Grade III/IV cardiac problems as defined by the New York Heart
Association Criteria. (e.g. congestive heart failure, myocardial infarction within 6
months of study)

- Medical, social or psychological factors interfering with compliance.

- Patients who have undergone major surgery for any cause less than 4 weeks prior to
study entry.

- Patients taking Coumadin® or other agents containing warfarin, with the exception of
low dose Coumadin® (1 mg or less) administered prophylactically for maintenance of
in-dwelling lines or ports.

- Any peripheral neuropathy > Grade 1.

- Patients with unresolved diarrhea > Grade 1.

- Patients may not have a history of an allergy to sulfonamide drugs.

- Patients may not have active peptic ulcer disease or other contraindications to
chronic NSAID use or aspirin use.

- Patients with lactose intolerance.

- Patients taking full-dose NSAIDs, including aspirin, regularly for any reason (e.g.,
arthritis,history of TIA or myocardial infarction). Patients taking cardiac
preventive dose ASA (<81mg daily) are eligible. Patients should stop taking any
other NSAIDs 14 days prior to receiving first dose of Celecoxib.

- Patients with hypersensitivity to COX-2 inhibitors, NSAIDS or salycilate.

- Patients taking fluconazole or lithium.