The sacrum is a bone at the back of the pelvis between the hip bones. A sacral fracture can cause symptoms including lower back and buttock pain, swelling, and reduced bowel and bladder control.

Medically reviewed by Brigid Dwyer, MD Key Takeaways The L5-S1 joint can be vulnerable to misalignment or injury. Common causes of pain at L5-S1 include disc herniation and spondylolisthesis.Pain from ...