Why is lower back pain common in the first few days after a miscarriage?

Patient's question:

After a miscarriage, for the first few days, I experienced lower back pain and a heavy feeling in the lower abdomen, with only a very small amount of bleeding. It has been 12 days now, and there is still minimal bleeding, along with small films and blood clots. I have been taking Gongxuening. On August 6th, three days after the gestational sac was expelled, I caught a cold and had a fever of 39°C. I took Fenka tablets and Xin'anmameimin tablets (II) to reduce the fever. The vaginal bleeding has been equal to the amount of a normal menstrual period. An ultrasound showed a 1 cm thick endometrium, and blood tests indicated high levels. The doctor recommended visiting the internal medicine department for follow-up and discharged me after 5 days of taking Metronidazole and Levofloxacin. Ten days later, my temperature rose again to 37°C, so I went to the hospital for blood tests, which were still slightly elevated. I was prescribed Cefotiazole for three days and had another ultrasound. The ultrasound showed the uterus to be 5.2 cm long, 4.8 cm wide, and 3.2 cm thick, with normal size and shape, uniform muscle layer echoes, and a clear endometrial line. There was a 0.9 cm thick endometrium, and a 0.7 cm deep liquid dark area was observed at the back of the uterus. The doctor said no obvious objects were seen inside the uterus, but it has been 11 days since the medication-induced miscarriage. Currently, there is only a very small amount of bleeding, with occasional small

Doctor's answer:

Hello, after taking medication for an abortion, it is normal to have a small amount of irregular vaginal bleeding within a few days. In your case, it is possible that the medication was not fully effective, so it is recommended that you visit the hospital for a follow-up examination. An ultrasound can be used to check if there is any residual tissue. If necessary, further medication treatment can be administered. Additionally, patients should develop a regular lifestyle, adhere to treatment, maintain a light diet, and engage in aerobic exercise to boost their immunity and reduce the risk of illness.