There is a connection between spinal health and digestive issues like constipation. The spine plays a central role in the body’s overall function, housing the spinal cord which is essential for communication between the brain and the rest of the body. When issues arise within the spine, they can disrupt the delicate balance of signals that govern bodily processes, including digestion. This disruption can manifest as constipation, linking these two seemingly separate systems.
The Spine-Gut Connection
The digestive system’s functions are controlled by a complex network of nerves. This network includes the autonomic nervous system, which operates without conscious thought, and the enteric nervous system. The autonomic nervous system has two main branches: the sympathetic and parasympathetic systems. The sympathetic nervous system inhibits digestion, while the parasympathetic nervous system promotes digestion by stimulating gut motility and secretion.
Nerves regulating gut function originate from or pass through the spinal column. Parasympathetic nerves stimulating bowel motility connect to the bowel via nerves in the sacral spinal cord. The enteric nervous system, within the gastrointestinal tract, directly controls gut motility and coordinates rhythmic muscle contractions (peristalsis) that move food along the digestive tract. Extrinsic nerves from the autonomic nervous system influence this intrinsic system. Damage to these nerve pathways can disrupt muscle contractions, slowing stool movement and leading to harder, difficult-to-pass stools.
Specific Spinal Issues and Their Impact
Various spinal problems can directly or indirectly contribute to constipation by interfering with nerve signals to the colon. A herniated disc can compress or irritate nerves of the spinal cord, disrupting signals that regulate bowel movements. This is especially impactful when it affects nerves in the lumbar region that control bowel function. Large disc herniations, particularly in the lower back, may lead to constipation.
Spinal cord injury (SCI) frequently results in bowel dysfunction, including constipation. The severity and location of the injury dictate the specific bowel problems. For instance, injuries above the T11/T12 level can cause spasticity in rectal and sphincter muscles, leading to stool retention and constipation. Conversely, injuries at or below T11/T12 may result in flaccid muscles and slower stool propulsion, also contributing to constipation. In both cases, the normal transit time of food through the colon is prolonged, leading to drier, harder stools.
Spinal stenosis can affect bowel movements by compressing the nerves that control bowel function. This narrowing can irritate or pinch the spinal cord or the nerve roots branching off it. Severe cases or those involving cauda equina injury can impact the smooth muscles of the bowel. Spondylolisthesis, where one vertebra slips forward over another, can similarly lead to nerve compression and bowel issues.
Cauda equina syndrome (CES) is a condition where the bundle of nerves at the lower end of the spinal cord (the cauda equina) becomes compressed. These nerves are responsible for sensation and control of movement in the lower body, including bowel function. Compression of these nerves can severely impair their ability to function, resulting in symptoms like severe constipation, loss of sensation around the anus, and difficulty controlling bowel movements. This condition is considered a medical emergency due to the potential for permanent nerve damage if untreated. Reduced physical activity due to spinal pain can also indirectly contribute to constipation, as movement helps stimulate the digestive system.
Beyond the Spine: Other Causes and Next Steps
Constipation is a common issue with a variety of causes beyond spinal problems. Dietary factors, such as insufficient fiber intake, and inadequate hydration are common contributors. A lack of physical activity can also slow down the digestive system. Certain medications, including some pain relievers (opioids), antidepressants, and iron supplements, are known to have constipation as a side effect.
Other medical conditions can also lead to constipation, such as irritable bowel syndrome (IBS), an underactive thyroid (hypothyroidism), or diabetes. Changes in daily routine, travel, stress, or even ignoring the urge to have a bowel movement can also play a role. Given the diverse origins of constipation, it is important to seek proper diagnosis from a healthcare professional if it becomes persistent or severe.
A doctor will begin by reviewing medical and family history and performing a physical examination, which may include checking for abdominal tenderness or a rectal exam. Depending on the symptoms and initial findings, further diagnostic tests might be ordered. These can include blood, stool, and urine tests to rule out other conditions, along with imaging tests like X-rays, CT scans, or MRI to visualize the spine and digestive tract. Bowel function tests, such as colorectal transit studies or anorectal manometry, may also be used to assess stool movement and anal sphincter function. Consulting a doctor is especially important if constipation is accompanied by severe back pain, neurological symptoms like numbness or weakness, or changes in bladder control, as these could signal a more serious underlying spinal condition.