If there is no allergy to seafood, there is no absolute contraindication to eating seafood after rectal cancer surgery, only need to pay attention to the consumption amount and cooking method; if allergic to certain seafood, need to avoid such seafood. After 2-3 days after rectal cancer surgery, you can eat liquid food after gas and bowel movement, turn to semi-liquid food after one week, observe until two weeks, if there is no special situation, you can gradually transition to normal diet. At this time, you can start to take in some seafood. There is no clear regulation on which kind of seafood can be eaten after rectal cancer surgery, which can be determined according to physical condition and personal preference. Generally speaking, the physical condition of postoperative patients is usually weak, in order to help the body to recover, those who are not allergic to seafood can eat some seafood rich in high-quality protein such as shrimp, tuna, wahoo and other seafood appropriately. Allergic to certain seafood, need to avoid eating this kind of seafood. Because some patients will be accompanied by postoperative digestion and absorption disorders, seafood consumption should pay attention to the cooking method, try to make seafood porridge, seafood egg custard and other easily digestible food, but also need to pay attention to the amount of food. If abdominal pain, diarrhea and other physical discomfort occurs after eating seafood, it is necessary to go to the hospital in a timely manner.