It takes about six weeks for all organs of the body, except the breast, to return to their pre-pregnancy state after childbirth, which means that the belly should be able to retract in about six weeks. If a mother’s belly has not returned to its pre-pregnancy state 42 days after delivery, common causes are mainly obesity and separation of the rectus abdominis muscle. Obesity requires weight loss, and losing one pound per week during the breastfeeding phase will not affect the quality of breastfeeding. If the belly does not recover due to separation of the rectus abdominis muscle, the abdominal shape needs to be repaired by strengthening the abdominal muscles with the correct and appropriate amount of exercise. Usually the greater the degree of separation, the weaker the strength of the rectus abdominis muscle. If the separation is more than 3cm and does not heal completely six months or even a year after delivery, you must seek professional help for exercise or treatment. Because the separation of the rectus abdominis means that the abdominal muscles have less support for the trunk, the burden on the muscles of the back will increase, making it easy for low back pain to develop, even into chronic pain. It may also lead to a downward shift of internal organs, such as gastroptosis, with symptoms such as nausea, vomiting and indigestion.