Primary objectives: Use both listed and relatively safe drug, Silymarin,s to improve the intestinal side effect of the patients undergoing FOLFIRI chemotherapy.

Primary Objective:

Use both listed and relatively safe drug, Silymarin, to improve the intestinal side effect of the patients undergoing FOLFIRI chemotherapy.

Patient Selection and Enrollment:

Number of Subjects: Eligible patients will be randomized in 2 arms in the ratio of 1:1, to reach approximately 70 patients in total.

Plan of the Study:

Study Design This is an open-label, randomized, comparative, double arm, single center study to assess efficacy of Silymarin as adjuvant therapy on metastatic colorectal cancer patients undergoing FOLFIRI chemotherapy in Taiwan.

Subject Number Eligible patients will be randomized in 2 arms in the ratio of 1:1, to reach approximately 70 patients in total.

Study Schedule Study date: the time getting approval letter issued by both regulatory authority and institutional review board (IRB) Duration of study: From the date of the IRB was approved till the 70th patient was collected.

Duration of Enrollment: From the date of the IRB was approved till the 70th patient was collected.

Duration of treatment: From the 1st patient starting chemotherapy till the 70th patient finishing the 6th cycle chemotherapy.

Duration of follow-up: From the 1st patient starting chemotherapy till 3 months after the 70th patient finishing the 6th cycle chemotherapy

Inclusion Criteria:

1. The patient who is between 20 to 80 years old
2. The patient who is diagnosed metastatic colorectal cancer and received chemotherapy with FOLFIRI regimen
3. The female patient should not be pregnant or breast-feeding
4. The patient who has no severe co-morbidity, such as cardiovascular, cerebrovascular, malignant hypertension, renal and hepatobiliary disease.
5. The patient who has no associated drug allergy to this trial.
6. The patient who is in compliance with prescribed medication.
7. The patient who is willing to sign the permit of the clinical trial.

Exclusion Criteria:

1. The patients who do not meet the main inclusion criteria or are not willing to sign the permit.
2. The patient who has viral hepatitis or carrier with impaired liver function.