To study how safe and effective is Irinotecanin treatment of colorectal cancer patients.

Intervention1: Irinotecan injection: ?Irinotecan injection 180 mg/m2 IV over 90 min, on Day 1, Day 15, Day 29 of each cycle.
Combination Drug:
?Leucovorin 200 mg/m2 IV over 2 hrs, on Day 1, Day 2, Day 15, Day 16, Day 29, and Day30 of each cycle.
?5-Fluoro Uracil bolus 400 mg/m2 IV bolus, on Day 1, Day 2, Day 15, Day 16, Day 29, and Day 30 of each cycle.
?5-Fluoro Uracil infusion 600 mg/m2 IV over 22 hrs, on Day1, Day 2, Day 15, Day 16, Day29, and Day 30 of each cycle.
Control Intervention1: NIL: NIL
Primary outcome(s): Overall Objective Response Rate (ORR) by RECIST criteria version 1.1Timepoint: Measured at baseline, before initiation of 3rd cycle (Day85), at the end of 6th cycle (Day240) and if required at the end of the study (1 year)