Constipation Severity Tracks With Low Back Pain in Herniated Disc Patients

Patients with lumbar disc herniation who also live with chronic constipation report more severe low back pain when their constipation symptoms are worse, according to a hospital-based cross-sectional study published in BMC Musculoskeletal Disorders. The research, led by Shuo Duan and Junyi You with colleagues, examined 200 patients diagnosed with both conditions and measured how bowel-related characteristics lined up with pain intensity. Because the study captured participants at a single point in time, it documents statistical associations rather than proving that constipation drives back pain or the reverse.

The participants completed a battery of standardized assessments. Pain severity was scored with a visual analogue scale, disability was measured with the Oswestry Disability Index, and constipation burden was quantified with the Wexner Constipation Score. Stool consistency was rated on the Bristol Stool Form Scale, and patients also reported how long they had experienced constipation, how much dietary fiber and water they consumed daily, how much time they spent physically active, and whether they used analgesics. The mean pain score across the group was 6.24 with a standard deviation of 2.28, the mean Wexner score was 14.07 with a standard deviation of 5.64, and the mean Oswestry Disability Index was 40.31 percent with a standard deviation of 9.73 percent, indicating substantial pain and moderate disability in this cohort.

The single strongest signal in the data involved the Wexner Constipation Score, a validated questionnaire that tallies constipation symptoms across several domains. The researchers found a strong correlation between Wexner scores and visual analogue scale pain scores, with a Pearson correlation coefficient of 0.861 and a P value below 0.001. In plain terms, patients who reported more frequent or more severe constipation symptoms tended to report more intense low back pain. Correlation of this magnitude is notable, though the cross-sectional design means the direction of the relationship cannot be determined from these data alone.

To test which variables held up independently, the team ran multiple linear regression analyses on the complete dataset. Four characteristics remained statistically associated with pain severity after accounting for the others: Wexner score, Bristol stool score, dietary fiber intake, and daily water intake. The Wexner score carried a regression coefficient of 0.290 with a P value below 0.001, meaning higher constipation symptom burden was associated with higher pain scores. Bristol stool score carried a coefficient of -0.208 with a P value below 0.001, indicating that softer stool consistency, reflected in higher Bristol ratings, was associated with lower reported pain.

The two lifestyle variables pointed in the same direction. Greater dietary fiber intake was associated with lower pain severity, with a regression coefficient of -0.045 and a P value of 0.011. Higher daily water consumption was likewise associated with lower pain scores, with a coefficient of -0.0018 and a P value below 0.001. The full regression model accounted for a striking share of the variation in pain scores, with an R-squared value of 0.799, meaning the included variables together explained roughly 80 percent of the variance in visual analogue scale scores within this sample. The authors caution, however, that such a model describes association within the cohort and cannot establish causal pathways.

What the study does not establish is equally important. Because every participant was assessed once, the findings cannot show whether constipation preceded the back pain, whether severe back pain and reduced mobility worsened bowel habits, or whether both share an underlying cause. The authors explicitly call for longitudinal and interventional studies to clarify the temporal and causal relationships. The sample was also limited to patients with both lumbar disc herniation and chronic constipation at a single hospital setting, so the results may not generalize to back pain patients without constipation or to constipated patients without spinal pathology. Duration of constipation, physical activity time, and analgesic use were collected as study variables, but the reported regression results highlight the four characteristics above as the ones that remained independently associated with pain severity.

Clinically, the work suggests that bowel symptoms deserve attention when clinicians evaluate pain severity in patients with lumbar disc herniation and chronic constipation. The strong correlation between the Wexner Constipation Score and the visual analogue scale indicates that these two measures move together closely in this subgroup, and the independent contributions of stool consistency, fiber intake, and water intake hint that modifiable dietary factors may be part of the picture. Whether improving bowel function would ease back pain, however, remains untested, and the authors are careful not to claim therapeutic benefit from an observational design.

The study was registered as not applicable for clinical trial purposes, reflecting its observational, cross-sectional nature in which participants were not assigned to any health-related intervention. Published as open access research on 3 November 2026, the article appears in BMC Musculoskeletal Disorders, a journal covering musculoskeletal conditions. For now, the practical takeaway is descriptive: in patients carrying both diagnoses, constipation severity and pain severity are tightly linked in the data, and the authors argue that this pattern justifies follow-up studies designed to untangle which comes first and whether intervening on bowel health could matter for pain outcomes.

Subject of Research: Associations between constipation-related characteristics and low back pain severity in patients with lumbar disc herniation and chronic constipation

Article Title: Association of constipation-related characteristics with low back pain severity in patients with lumbar disc herniation and chronic constipation: a cross-sectional study

Article References: Duan, S., You, J., Xu, S., Xu, B., Shi, X., Shen, X., & Li, Y. (2026). Association of constipation-related characteristics with low back pain severity in patients with lumbar disc herniation and chronic constipation: a cross-sectional study. BMC Musculoskeletal Disorders. https://doi.org/10.1186/s12891-026-10606-5

Image Credits: AI Generated

DOI: 10.1186/s12891-026-10606-5

Keywords: lumbar disc herniation, chronic constipation, low back pain, cross-sectional study, Wexner Constipation Score, Bristol Stool Form Scale, visual analogue scale, Oswestry Disability Index, dietary fiber, water intake, regression analysis, BMC Musculoskeletal Disorders