The pelvic floor is a layer of muscles that stretches like a hammock from the pubic bone at the front of the pelvis to the base of the spine in the back. These muscles support the weight of the pelvic organs and enable everyday activities like walking and sitting. Ligaments within the pelvis hold the organs in place.

The pelvic floor muscles also play a crucial role in the functioning of pelvic organs. For example, bands of muscle encircle the urethra (the opening you urinate through) and bowel. These bands are called sphincters. Sphincters control the release of urine and feces. Other muscles surrounding these organs control the filling and emptying of the bowel and bladder.

Muscles throughout the pelvis also work when a woman gives birth. Some of these same muscles contribute to the enjoyable sensations of female orgasm.

Damage or weakness in these muscles can interfere with all of these functions. One of the most obvious signs of damage is a prolapse.

Think of the pelvic floor as a mesh of muscles, like a nylon stocking. When these muscles are weakened or damaged, runs or even holes appear in the mesh and it can no longer support the pelvic organs. A prolapsed organ is an organ that has shifted position and begun to protrude through this mesh. Most commonly, prolapsed organs press down against the vagina, since this is the largest opening to the pelvic floor. This causes a bulge in the wall of the vagina. In severe cases, a prolapse can push part of the vaginal wall out through the vaginal opening.

• Types of prolapse