Which of the following symptoms is least likely associated with endometriosis?

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, often leading to a variety of symptoms primarily associated with the menstrual cycle and pelvic region. Among the symptoms listed, frequent urination is the least likely to be directly associated with endometriosis.

Painful menstruation, also known as dysmenorrhea, is a common symptom of endometriosis due to inflammation and adhesions that can affect the pelvic organs. Heavy menstrual bleeding, or menorrhagia, can also occur because the presence of endometrial-like tissue outside the uterus can interfere with normal menstruation and increase bleeding intensity and duration.

Constipation is associated with endometriosis as well, particularly if the endometrial-like tissue is located on or near the bowel, leading to discomfort and changes in bowel habits due to the pressure and inflammation in the pelvic area.

Frequent urination might occur if endometriosis affects tissues near the bladder, but it is not as universally recognized as a core symptom of the condition compared to the others listed. Thus, frequent urination is the symptom that is least likely to be associated with endometriosis, making it the correct choice in this instance.