Allergy after anal preservation surgery for rectal cancer is usually caused by allergens stimulation, such as dust, drugs, etc. It should be detached from the allergens immediately and treated with anti-allergic drugs under doctor’s guidance, such as chlorpheniramine maleate tablets and loratadine tablets. 1. Chlorpheniramine Maleate Tablets: Chlorpheniramine Maleate Tablets can be used for skin allergies, drug and food allergies, etc. Taking Chlorpheniramine Maleate Tablets may cause thirst, drowsiness, palpitations (rapid heartbeat, often accompanied by panic) and other phenomena, and is forbidden to those who are allergic to the drug, those who are engaged in high-altitude work, and those who have high blood pressure. 2. Loratadine Tablets: Loratadine Tablets can be used to relieve allergic symptoms, some patients can see headache, fatigue, dry mouth and other phenomena after use, pregnant and lactating women should be cautious, and those who are allergic to the drug are forbidden to use it. It is suggested that patients with allergy after rectal cancer surgery should not take medication without authorization, and should go to the hospital for examination in time, and choose reasonable treatment methods under the guidance of professional doctors.