The composition of the alimentary canal mainly includes the oral cavity, pharynx, esophagus, stomach, small intestine and large intestine. 1. Oral cavity: the beginning of the alimentary canal, forward to the outside world through the lips of the mouth surrounded by the cleft, backward through the pharyngeal isthmus and pharynx. It can include the lips, cheeks, palate, teeth, tongue and other parts. 2. Pharynx: it is the enlarged part of the upper end of the alimentary canal, which can be divided into nasopharynx, oropharynx and laryngopharynx. 3. Esophagus: the narrowest part of the alimentary canal, which can be divided into three parts: neck, chest and abdomen. 4. Stomach: the most enlarged part of the alimentary canal, connected to the esophagus and duodenum. It can be divided into four parts: cardia, fundus, body and pylorus. 5. Small intestine: the longest part of the alimentary canal, which can be divided into duodenum, jejunum and ileum. 6. Large intestine: is the lower part of the digestive tube, which can be divided into five parts: cecum, appendix, colon, rectum, and anal canal. Abnormal symptoms of the digestive tube need to go to the hospital in a timely manner, to clarify the cause of the disease to follow the doctor’s instructions for treatment, to avoid self-medication.