Final answer:
The condition most likely representing the described symptoms of a postpartum woman with intense pelvic pain and hypoechoic uterus with irregular endometrium on ultrasound is endometritis, an inflammation of the uterine lining. The correct answer is option: c. Endometritis.
Step-by-step explanation:
A 3-day postpartum woman complains of intense pelvic pain, and sonographic findings suggest a hypoechoic uterus with an irregular endometrium. This condition most likely represents endometritis. Endometritis is an inflammation of the endometrial lining of the uterus, often occurring after childbirth, and can cause severe pelvic pain and irregularities in the endometrial appearance on ultrasound.
It is distinguishable from other conditions such as adenomyosis, which is the growth of endometrial tissue into the muscle of the uterus; a degenerating submucosal leiomyoma, which is a type of non-cancerous tumor of the uterus; and endometrial hyperplasia, which is the thickening of the uterus lining caused by an excess of estrogen.
Common signs and symptoms of endometriosis include chronic pelvic pain, which can be severe during menstruation, infertility, diarrhea or constipation, chronic fatigue, nausea, and irregular menstrual bleeding. However, it is characterized by endometrial-like tissue growing outside the uterus and would not typically present immediately postpartum as in the case described.