Sciatic hernias are rare. When a sciatic hernia does develop it affects the pelvis, causing chronic pelvic pain. Women are more affected by sciatic hernias due to the wider shaper of the pelvic bone and its natural passageways. A sciatic hernia can affect the small intestine, causing intestinal blockage. The urinary tract can be affected if the bladder is inside of the hernia sac. An ovary and fallopian tube can be affected for similar reason.