I looked this up and it may be worth consulting with a CCSVI IR before you take action.
Description: The pelvic circulation for the sigmoid colon and rectum is derived by the inferior mesenteric a. from the aorta, and the remaining viscera derive blood flow via the common iliac a., except for the ovarian a. which are from the abdominal aorta. The external iliac a. separates from the internal iliac a. just above the pelvic inlet, and courses anteriorly into the lower extremity by passing beneath the inguinal ligament. At the level of division of the external a., the internal iliac a. has three branches, the iliolumbar a., the lateral sacral a., and the large superior gluteal a. , the latter exiting above the piriformis m. Distally, at the lower margin of the piriformis m., seven major branches are visible anteriorly in the pelvis: the obturator a., superior vesical a., the uterine a., the inferior vesical a., the middle rectal a., the internal pudendal a., and the inferior gluteal a. Posteriorly, the inferior rectal a. branches from the internal pudendal a. supply the anal canal. The venous collecting system in the visceral pelvis, in contrast to most other regions, begins from plexuses about the bladder, ovary, uterus and cervix, and the anorectal region. These tributaries coalesce into identifiable, although variable veins. As with the a., the ovarian vein courses laterally through the suspensory ligamant of the ovary, draining directly into the vena cava on the right, and into the renal v. in the left. Distally, the larger of the venous plexus are the inferior mesenteric v., draining to the portal v., and the middle and inferior rectal v. These drain to the internal pudendal v. which courses cephalad, connecting with the inferior gluteal v. and the lateral sacral v. to form the internal iliac v. This v. joins the external iliac v. at the pelvic inlet forming the common iliac v.. In the perineum, the internal pudendal v. collects blood from the bulbospongiosis m., the bulb of the vestibule and greater vestibular gland, the superficial transverse perineal m., the levator ani m., and the external anal sphincter. During pregnancy, the normally tortuous uterine vessels become elongated and enlarged to meet the new metabolic demands.
Were you ever checked for renal stenosis or May Thurner?