Constipation and Low Back Pain Relationship

Understanding the Mechanisms

Severe constipation or fecal impaction can cause distension of the rectosigmoid colon, creating pressure on adjacent lumbosacral structures and nerves, potentially manifesting as low back discomfort, as noted by the National Comprehensive Cancer Network 1, 2

The American College of Physicians recommends systematically excluding serious pathology, including cauda equina syndrome, malignancy indicators, spinal infection, and vertebral compression fracture, before attributing low back pain to constipation 3, 4, 5
It is essential to distinguish constipation-related low back pain from radiculopathy and spinal stenosis, as true radiculopathy presents with leg pain below the knee in a dermatomal distribution, and spinal stenosis causes neurogenic claudication 3, 4, 5

When constipation is suspected to be the cause of low back pain, the National Comprehensive Cancer Network suggests assessing constipation severity, identifying contributing factors, and managing constipation with stimulant laxatives, osmotic laxatives, increased fluid intake, and physical activity 1, 2
The Praxis Medical Insights guideline recommends reassessing pain after bowel function normalizes and pursuing standard evaluation for nonspecific low back pain if pain persists 5

The American College of Physicians advises against routinely imaging for nonspecific low back pain, as it does not improve outcomes and may lead to unnecessary interventions, unless red flags are present 4, 5
It is crucial not to assume constipation is the cause of low back pain without proper evaluation, as most low back pain is musculoskeletal in origin, and constipation should be considered contributory only after excluding more common causes 3, 4
The National Comprehensive Cancer Network notes that medication-induced constipation, particularly with opioid analgesics, should not be overlooked, as it can create a potential cycle where pain treatment worsens constipation, which may worsen pain 1, 2