Normally, the post-caesarean section discharge should have a bloody odor, and if you feel a foul or fishy odor, you may have a bacterial infection. If there is a large amount of bloody discharge with a fishy odor 2 weeks after the cesarean section, there may be a combination of infection with residual placenta-membrane in the uterine cavity. If there is fever, abdominal pain and a fishy odor after 2 weeks of cesarean section, it may be myometritis or endometritis. If there is still bloody discharge with fishy odor 6 weeks after delivery, it is considered that the uterus is not well recuperated, and ultrasound examination and routine blood tests are needed. Ultrasound suggests that there is residue in the uterine cavity, which needs to be cleared promptly after anti-inflammation, otherwise there is a risk of hemorrhage. If the diagnosis of uterine myositis or endometritis is confirmed, hospitalization is recommended for infusion and application of a sufficient amount and course of broad-spectrum antibiotic treatment.