Pelvic Splanchnic Nerves

The descending and sigmoid colon, the rectum, and all pelvic organs receive their parasympathetic preganglionic input via the Pelvic Splanchnic nerves. The pelvic splanchnic nerves spring from the anterior rami of the second, third, and fourth sacral nerves shortly after their emergence from the pelvic sacral foramina. The contribution from the third sacral nerve is usually the largest.