I think this drug as other is absorbed through the small intestine

I agree with Dr. Luis that the rifampicin is easily absorbed through the small intestine. However, the drug also interacts with other drugs. So, you should check the label or drug information through available sources. Usually drug absorption does not take place in the colon but since more than 60% of the relatively active metabolite is excreted through the feces, it can be effective for tuberculous enteritis affecting the cecum to proximal colon as well. 

Thanks Dr. Luis thanks alot wang. 

Actually Im designing a experiment to check in-vitro colonic drug release .. So I wanted to ask that can use Rifampicin in my experiment ! because I have the pure salt of this drug.