The clinical experience of Department Director Li Yan in treating colorectal cancer is presented. Li Yan posits that the fundamental pathogenesis of colorectal cancer stems from the depletion of vital qi and the prolonged stagnation of various pathogenic factors in the intestines. The primary treatment principle is to "strengthen vital qi and eliminate pathogenic factors". Based on individual patient conditions， treatment is adjusted with flexibility， placing emphasis on the therapeutic approach of "promoting smooth flow as supplementation". A holistic treatment strategy is used， integrating both internal and external treatment， treating both the lungs and intestines， and harmonizing the internal zang-fu organs. This results in the removal of pathogenic factors and the restoration of the body's balance， leading to significant therapeutic outcomes. A proven case is presented .