Clinically speaking, there is no absolute relationship between smoking and constipation, and smoking does not cause constipation. There are many causes of constipation, usually related to certain diseases and non-disease factors. 1, non-disease factors: 1, drug factors: some drugs may affect intestinal peristalsis, resulting in constipation, such as vincristine drugs, such drugs have obvious toxicity to the autonomic nerve governing intestinal peristalsis, can cause gastric emptying and intestinal motility disorders, thus causing constipation; 2, dietary factors: if the diet is too fine, fiber intake is insufficient, while drinking less water, resulting in weakened intestinal peristalsis, can also cause constipation; 3, physical condition factors: for smoking and constipation. 3, physical condition factors: for the elderly group with high smoking age, due to long-term smoking history, may cause respiratory diseases, which in turn lead to their own poor physical condition, usually less activity, resulting in slow peristalsis of the gastrointestinal tract function, also easy to cause constipation. Second, disease factors: 1, neurological diseases: usually suffer from cauda equina nerve damage, cervical spinal cord injury patients, there will be a serious loss of nerve function, will also cause constipation; 2, intestinal diseases: patients suffering from anal fissures, perianal abscesses and ulcers, proctitis, colon good, malignant tumors and other diseases, will lead to anal sphincter spasm, painful defecation, will also cause constipation. Therefore, smoking and constipation usually do not have too much to do with each other, but if you smoke for a long time, your body may develop some diseases of the respiratory system, which can seriously affect your health condition. It is recommended to smoke less, eat more vegetables and fruits, drink more water, and strengthen exercise to promote gastrointestinal tract peristalsis, which can effectively avoid constipation.