Abdominal pain on the fourth day after medication abortion may be uterine contractions caused by residual embryonic tissue after medication abortion, and may also be pelvic inflammatory disease caused by medication abortion. Most women should not have abdominal pain on the fourth day after a medication abortion. If there is abdominal pain accompanied by excessive vaginal bleeding, consider that there is residual embryonic tissue, and you can go to the hospital to do an ultrasound to see the condition of the uterine cavity. If the residual tissue is more, you need to carry out a purging operation. In addition, if you do not pay attention to hygiene after the abortion, leading to bacteria into the pelvic cavity, it is easy to cause pelvic inflammation, this time will also appear abdominal pain, in this case you need to take anti-inflammatory drugs under the guidance of the doctor.