The endometrial biopsy involves sampling the uterus lining to check for abnormal cells related to menstrual irregularities, menopausal bleeding, hormone therapy effects, endometrial cancer, and precancerous changes. The procedure uses a catheter for tissue removal, causing mild cramping and potential post-procedure bleeding. Beforehand, inform your doctor if pregnant, on medications, or with bleeding disorders/allergies; consider stopping blood thinners.