The spinal cord also carries “autonomic” signals that control blood pressure, blood flow, breathing, sweating, bowel, bladder, sexual, and other autonomic functions.

• Bladder Paralysis and Spasticity. Spinal cord injury paralyzes the bladder. The bladder must be catheterized to drain urine. Indwelling catheters (such as a foley catheter inserted through the urethra) have a high risk of infections. Sterile intermittent catheterization is recommended but may be complicated by bladder spasticity or spontaneous contractions of the bladder. Bladder contractions can push urine into the kidney and this may lead to kidney damage. A drug called Ditropan suppresses bladder spasticity but have side effects such as dry mouth and eyes. Alternative approaches are available, including cutting the bladder sphincter so that urine drains freely into a condom catheter but this approach is not suitable for women. An approach that does not involve compromise of the urinary sphincter is placement of a suprapubic catheter or creation of a intestinal conduit from the abdominal wall to the bladder, i.e. a Mitrafanoff procedure.

• Bowel constipation and incontinence. The bowels usually operate without much voluntary control. However, spinal cord injury slows bowel activity and transit time of food in the gut. People use a variety of stimulants and suppositories to facilitate bowel activity. Bowel incontinence is a serious problem, often restricting social activity and employment options. A common technique is to establish a bowel routine to empty the gut on a set schedule. Artificial sphincters are available but the success rates of such procedures are still limited. Finally, alterations in secretion patterns can lead to indigestion, appetite changes, nausea, gallbladder stones, and other problems, especially in people with cervical spinal cord injury.

• Erection and ejaculation. Most people assume that spinal cord injury eliminates the possibility of sexual function. However, this is not true for a majority of people with spinal cord injury. Penile erection is a reflex and many men are able to have erections after spinal cord injury unless the injury involves the lower spinal cord or roots that control erection. Recent studies suggest that Viagra works for people with spinal cord injury. Vibrators or electrical stimulation can be used to facilitate ejaculation. Due to sphincter spasticity or poor coordination of the bladder sphincters, the ejaculate often goes into the bladder rather than outward. However, with a combination of electroejaculation and semen collection, it is possible to collect ejaculates from nearly all males. While spinal cord injury may interfere with menstrual cycles, a vast majority of young women with spinal cord injury remain fertile and can conceive.