Clinical Relevance of the Feces Sign in Small-Bowel Obstruction Due to Adhesions Depends on Its Location

Abstract

OBJECTIVE. The objective of our study was to evaluate if the feces sign can be used to predict successful nonoperative treatment or progression to ischemia in patients with small-bowel obstruction (SBO) due to adhesions. MATERIALS AND METHODS. For this single-center retrospective observational study involving a blinded independent review by two radiologists of 237 consecutive CT examinations of 216 patients with SBO due to adhesions (age: mean, 70.9 years; median, 74 years; interquartile range, 62–84 years), the location of the transition zone (TZ), number of TZs, and presence and location of the feces sign relative to the TZ were recorded. The reference standard for diagnosing ischemia was surgical and pathologic findings (n = 108 CT examinations) or, when treatment was nonoperative (n = 129 CT examinations), clinical outcome. Factors associated with successful nonoperative treatment and ischemia were identified by univariate and multivariate analyses. RESULTS. A feces sign was seen in 88 of 237 CT examinations (37.1%). The feces sign was at the TZ, which we refer to as the “TZ feces” sign, in 82 of 88 (93.2%) patients; between two TZs, which we refer to as the “trapped feces” sign, in 14 (15.9%) patients; and in both locations in eight (9.1%) patients. By univariate analysis, an isolated TZ feces sign was associated positively with successful nonoperative treatment (odds ratio [OR], 3.37; 95% CI, 1.71–6.66; p < 0.001) and negatively with ischemia (OR, 0.33; 95% CI, 0.13–0.85; p = 0.02). Combined TZ and trapped feces signs were associated with ischemia (OR, 24.16; 95% CI, 2.86–203.89; p = 0.003). By multivariate analysis, regardless of the location of the feces sign, the feces sign was not significantly associated with successful nonoperative treatment or progression to ischemia. CONCLUSION. The feces sign is common and helps to identify the TZ. Among the CT signs of SBO, the feces sign does not independently help to predict successful nonoperative treatment or progression to ischemia.