This morning, there was a small amount of pinkish discharge on my underwear, and my lower back feels slightly sore. What could be the cause, and what should I do?

There may be a small amount of pinkish discharge in the underwear in the morning, along with mild lower back soreness. This could be caused by ovulation bleeding, pelvic inflammatory disease, uterine fibroids, or other reasons. Treatment options include general management, medication, or surgery. A detailed analysis is as follows:

1. Ovulation Bleeding

Ovulation is the process in which the ovaries release a mature egg, typically occurring in the middle of the menstrual cycle. During ovulation, the mature egg is released from the ovary, accompanied by follicle rupture and egg expulsion, which may result in slight bleeding. This type of bleeding is usually minimal, appearing as pink or light red discharge, and may be associated with mild abdominal pain and other discomforts.

2. Pelvic Inflammatory Disease (PID)

PID can damage organs such as the uterus, fallopian tubes, and ovaries, leading to abnormal bleeding and changes in vaginal discharge. Under a doctor's guidance, patients may take medications such as clindamycin hydrochloride capsules or levofloxacin hydrochloride capsules for treatment.

3. Uterine Fibroids

Uterine fibroids are tumors arising from the muscular layer of the uterine wall. Structural changes in the uterus due to fibroids may lead to heavy menstrual bleeding or irregular bleeding. Patients with more severe symptoms may require treatments such as hysteroscopic surgery or open abdominal surgery.

In addition to the above causes, similar symptoms might also result from endometriosis, cervical tumors, or endometrial tumors. Since various local pathological factors may be involved, it is recommended to seek timely medical attention and professional treatment.