There are the following reasons for abdominal pain more than 20 days after abortion: first, incomplete abortion, abortion surgery residual pregnancy products in the uterine cavity, will induce uterine contraction, which will lead to abdominal pain; second, infection after abortion, if abdominal pain accompanied by fever or purulent discharge, most of them are infections, need to carry out routine blood tests and antibiotic treatment; third, the most unwilling to encounter is the uterine cavity or cervical canal adhesion, abortion After the operation, the damage to the endometrium as well as cervical dilation may lead to endometrial as well as cervical adhesions. In this case, after the resumption of menstruation, it is possible that the blood may not flow out smoothly, leading to abdominal pain, which is also the result of contraction of the uterus stimulated by menstrual blood. Therefore, abdominal pain more than 20 days after abortion is related to the above-mentioned causes, and further examination is needed to confirm and then treat it.