Correlation of Preoperative Inorganic Phosphates and Operative Findings in Patients of Intestinal Obstruction: A Preliminary Prospective Observational Study

Background: Identifying intestinal ischemia in small-bowel obstruction (SBO) remains a diagnostic challenge. We evaluated whether serum inorganic phosphate measured before surgery correlates with intraoperative evidence of bowel ischemia in a pilot cohort. Methods: This prospective observational study was conducted at a tertiary center in India over 18 months. Adults (18?70 years) with clinically diagnosed SBO were enrolled (n=54). Admission serum inorganic phosphate (mg/dL) was recorded. Ischemia was assessed intraoperatively based on visual inspection. Associations were examined using chi-square, t-tests, and ROC analysis. Results: Among 54 participants, ischemia was confirmed in 18.9% (n=10). Mean phosphate was significantly higher in patients with ischemia (4.75 mg/dL) than in those without (3.48 mg/dL). A threshold of >3.5 mg/dL provided the best separation in this cohort, with an ROC AUC of 0.727 (95% CI 0.589?0.840). However, false positives were noted, with elevated phosphate seen in some non-ischemic patients. Conclusions: Elevated preoperative inorganic phosphate is associated with operative ischemia in SBO and may assist triage and decision?making. Larger cohorts should validate cutoffs and clinical integration.