It is possible for a person to gain weight after the appendix has been removed. The appendix is a blind tube in the digestive tract and is an organ that belongs to the degenerate body. Some people will be induced to have an attack of appendicitis due to fecal stones, stones, worm eggs, infection, etc. In cases of recurrent appendicitis that are more severe, the appendix can be removed for treatment. The appendix has no absorption function for nutrients, and the absorption of nutrients is normal after appendectomy, which does not affect the body’s weight and nutrient absorption. Some people have lost weight and gained weight after appendectomy, mainly due to the impaired intestinal function, such as irritable bowel syndrome, enteritis and imbalance of intestinal flora, which need to be treated for the disease.