Following a spinal cord injury (SCI), many individuals face secondary health conditions, with chronic constipation being a frequent challenge. Effectively managing bowel function is an aspect of post-injury care that influences overall health, independence, and quality of life. A consistent and well-structured bowel care program helps prevent constipation and its complications, establishing a predictable routine for long-term health maintenance.
The Connection Between the Spinal Cord and Bowel Function
The large intestine moves stool toward the rectum through coordinated muscle contractions called peristalsis. This process is controlled by nerves connecting the brain, spinal cord, and gut. The brain sends signals down the spinal cord that allow for voluntary control over the external anal sphincter, the muscle that holds stool until a person decides to have a bowel movement.
A spinal cord injury disrupts this communication system. The interruption of nerve signals between the brain and the lower digestive tract leads to neurogenic bowel dysfunction. This dysfunction impairs both the movement of stool through the colon and the ability to control defecation. The result is a significant slowing of stool transit time, which leads to constipation and a high risk of fecal incontinence.
The nature of the bowel dysfunction depends on the injury’s location. An injury to the upper spinal cord (above the T12 vertebra) results in a reflexic bowel. The reflex that triggers a bowel movement when the rectum is full remains, but the person cannot voluntarily control it. The anal sphincter muscle stays tight, and bowel movements occur as a reflex, often leading to incomplete emptying.
An injury to the lower spinal cord (at or below the T12/L1 vertebrae) causes an areflexic, or flaccid, bowel. This injury damages the nerves controlling the defecation reflex. As a result, the colon has reduced peristalsis, and the anal sphincter muscle becomes lax. This leads to very slow stool movement and a high risk of both constipation and accidental leakage.
Recognizing Complications and Symptoms
The signs of constipation after an SCI range from common symptoms to medical emergencies. Individuals may experience abdominal bloating, discomfort, a persistent feeling of fullness, and a loss of appetite. Common indicators include:
- Infrequent bowel movements
- Passing hard or lumpy stools
- The need to strain during evacuation
- A persistent feeling of fullness
- Loss of appetite
Chronic constipation can lead to more serious complications. Fecal impaction, where a hard mass of stool becomes stuck in the colon or rectum, is a concern that requires medical intervention. Over time, the strain from difficult bowel movements can also lead to hemorrhoids or rectal prolapse, where part of the rectum protrudes from the anus.
One of the most urgent complications is autonomic dysreflexia (AD), a medical emergency affecting individuals with injuries at the T6 level or higher. AD is triggered by a painful stimulus below the level of injury, and a full bowel is a common cause. Symptoms include a pounding headache, a rapid rise in blood pressure, profuse sweating above the injury level, and flushed skin. If not addressed by removing the stimulus, AD can lead to stroke or seizure.
Establishing a Bowel Management Program
A structured bowel management program is the foundation for preventing constipation. The goal is to establish a predictable schedule for bowel movements, aiming for a complete evacuation at a planned time every day or every other day.
Diet and fluid intake are central to managing stool consistency. A diet with adequate fiber is recommended to add bulk and softness to the stool, making it easier to pass. Proper hydration is also important, as fluids work with fiber to keep stool soft; however, fluid intake must be balanced with bladder management needs.
Medications are used to assist with bowel regularity. These are often used in combination to achieve the desired stool consistency and timing. Common types include:
- Stool softeners, such as docusate, which help to draw water into the stool.
- Osmotic laxatives, like polyethylene glycol, which pull more fluid into the intestines.
- Stimulant laxatives, including senna or bisacodyl, which act on the intestinal walls to trigger muscle contractions.
- Rectal medications, such as suppositories and mini-enemas, which stimulate the rectum to trigger evacuation.
Physical techniques are another component of a bowel program. Digital rectal stimulation involves gently using a gloved, lubricated finger to trigger the reflex that causes the rectal muscles to contract. For individuals with an areflexic bowel or severe constipation, manual removal of stool may be necessary to clear the rectum completely.
Consistency in timing and positioning aids the program’s effectiveness. Performing the bowel program at the same time each day helps train the body and establish a regular pattern. Using an upright position on a commode chair or toilet takes advantage of gravity to help with evacuation.
Surgical and Advanced Treatment Options
When a standard bowel management program is not sufficient to manage chronic constipation, surgical or advanced interventions may be considered. These options are for individuals who experience persistent issues like severe fecal impaction, incontinence that impacts quality of life, or recurrent autonomic dysreflexia.
One surgical option is the antegrade continence enema (ACE). In this procedure, a surgeon creates a small opening, or stoma, in the abdomen that connects to the beginning of the large intestine. A tube is inserted through this stoma, allowing for the administration of an enema solution that flushes the entire colon, resulting in a predictable and complete evacuation.
Another intervention is sacral nerve stimulation, which involves implanting a device that sends mild electrical pulses to the sacral nerves. These nerves influence the function of the rectum and anal sphincter. The stimulation can help improve muscle control and sensation, which may reduce fecal incontinence and regulate bowel function for some individuals.
In cases of severe bowel dysfunction, a colostomy may be the most effective solution. This surgery reroutes the end of the colon through a stoma in the abdominal wall. Stool passes out of the body through the stoma and is collected in an external pouch. This can provide a reliable system for bowel care, eliminating the risks of impaction and incontinence.