The study summarizes the clinical experience of Professor Zhu Ying,the inherited instructor of academic experience from the national veteran Chinese medicine experts,in the syndrome differentiation and treatment of ulcerative colitis from the theory of potential toxin.It is believed that the core pathogenesis of ulcerative colitis includes vital qi deficiencies leading to lingering pathogens,and collateral damages caused by the potential toxin.In view of that,we propose the treatment principles of treating and differentiating both syndromes and root causes by stages,controlling the development...