In conclusion, the relationship between smoking and the digestive organs is multifaceted. Cigarettes contain a variety of chemical compounds, and they exhibit variable effects, either directly or via the central nervous system, on tissue microcirculation, motor regulation, and including various systems, the immune system. The influence of smoking on the specific function of an organ may be modified under different experimental conditions. As far as the achievements of previous studies are concerned, some effects of smoking on the digestive system are still controversial. Further investigations are needed.