Risk factors associated with stool retention assessed by abdominal radiography for constipation

Objectives: To assess the reliability of applying a radiographic scoring system in estimating the severity of stool retention (SR) in hospitalized older adults with constipation, and to identify risk factors associated with clinical constipation and SR scores.

Design: Retrospective, case series study.

Setting: Southeast Ohio community hospital.

Participants: Adults 65 years or older with constipation or fecal impaction and abdominal radiographs available (N=122). Bowel obstruction was excluded.

Measurement: Radiographs were independently scored by four readers twice, "5" being the most severe, for each quadrant of an abdominal film; possible total score was 0 to 20. Clinical constipation was defined as an average SR score of 13 or higher. Intra-class correlation was used to measure inter-rater agreement.

Results: The overall inter-rater agreement on abdominal radiograph readings was 0.91, 95% confidence interval (CI)=0.88-0.93. Clinical constipation was associated with the use of statins and antimuscarinics by univariate logistic regression analysis. After adjusting for age, sex, residency, smoking history, oral laxatives, and self-reported constipation, the use of statins remained significantly associated with clinical constipation (OR=3.86, 95% CI=1.08-13.77, P=.036). Univariate linear regression analysis revealed that higher SR scores were associated with community residency, self-reported constipation, and the use of statins and antimuscarinics. After adjusting for the above confounders by multiple linear regression analyses, the use of antimuscarinics was independently associated with higher SR score (β=1.769, 95% CI=0.008-3.531, P=.049).

Conclusion: Abdominal radiography was reliable in assessing the severity of SR in older adults with constipation. The use of statins and antimuscarinics was associated with clinical constipation and greater SR.