不吸烟、戒烟者、吸烟者三种人群中具有不同的溃疡性结肠炎（溃结）发病率及患病相对危险性，性别、吸烟数量、是否戒烟、是否被动吸烟对溃结发病均有影响。吸烟者中溃结发病率低的原因可能与尼古丁能增强结肠粘液屏障的作用有关 Non-smoking, smoking cessation, smokers in three populations have different ulcerative colitis (UC) incidence and relative risk of illness, sex, number of smoking, whether to quit smoking, whether passive smoking on the incidence of ulceration are affected . The reason for the low incidence of ulceration in smokers may be related to the effect of nicotine on colonic mucosal barrier enhancement