The burning sensation in the anus after a bowel movement is usually caused by eating spicy and stimulating food, or by constipation, anal fissures, hemorrhoids, anal inflammation, anal tumors and other factors. If you have a burning sensation in the anus after a long period of time, with other symptoms, it is recommended to go to the hospital for anorectal examination to clarify the specific causes and timely treatment to improve the symptoms through dietary adjustment, medication or surgery. 1. Dietary stimulation: Patients who eat a lot of stimulating food, such as chili, onion, etc., may have a burning sensation in the anus after a bowel movement or with pain. The phenomenon of anal burning sensation or pain. It is recommended to adjust the diet and avoid spicy and irritating foods. 2. Constipation: Constipation leads to dry and hard stools, and hard feces can irritate the anus during defecation, resulting in burning sensation and pain in the anus after defecation. It is recommended to drink more water, and increase the intake of dietary fiber, and develop the habit of regular bowel movements. If the constipation is serious, you can use paraffin oil, lactulose and other drugs under the guidance of a doctor to promote the discharge of feces and relieve the discomfort; 3, anal fissure: due to small ulcers in the skin of the anal canal under the dentate line, defecation will stimulate the ulcer surface, which will lead to anal burning sensation, pain, bleeding and other discomfort after the stool, which can generally be relieved after a few minutes or hours. Acute episodes of anal fissures can be relieved by potassium permanganate solution after defecation, and chronic anal fissures can be treated by anal fissure resection; 4, hemorrhoids: hemorrhoids are the most common anal disease, which can be caused by perianal infection causing perivenous inflammation, causing the veins to lose elasticity and expand, plus the stimulation of defecation and discomfort such as burning sensation and bleeding after the stool. These patients can improve local blood circulation through hot water baths to relieve the discomfort. For patients with more serious hemorrhoids, they can be treated with sclerosing agents under the guidance of a doctor, such as phenol vegetable oil, sodium cod liver oil acid, or through surgery; 5. Anal inflammation: the anus is infected by bacteria, fungi, viruses, mycoplasma, chlamydia and other pathogens, causing inflammation, such as anal inflammation, anal sinusitis, etc. When defecation stimulates inflammation, anal burning sensation may occur. According to different pathogens, different antibiotics should be used for treatment, such as cephalosporins for bacterial infections and fluconazole for fungal infections. 6. Anal tumor: due to various stimuli such as environment, diet and lifestyle, tumors appear around the anus. The main treatment methods for anal tumor are radiotherapy and chemotherapy, which need to be selected according to the patient’s general condition and specific condition; if the anal tumor is relatively small and no metastasis has occurred, it can also be treated by surgical excision.