Usefulness of ultrasonographic evaluation of stool and/or gas distribution for the treatment strategy of chronic constipation

BACKGROUND AND AIM: This study aimed to evaluate the capability of ultrasonography to predict favorable outcomes of various medical therapies in patients with chronic constipation. METHODS: We enrolled 223 patients with chronic constipation (75 men, 148 women; mean age 62.9 ± 3.4 years). Transverse diameters of four segments of the colon (ascending [A], transverse [T], descending [D], sigmoid [S]), and the rectum [R]) were measured. The patients' stool and/or gas distribution was evaluated using the constipation index (CI) ([A + T + D + S + R]/5) and the left/right distribution ratio ([D + S]/[A + T]) according to our previous study. Patients were first treated with fiber‐ or osmosis‐based laxatives for 2 weeks. When constipation was not alleviated, stimulant‐based laxatives were added, and the patients were followed for another 2 weeks. RESULTS: Based on their clinical courses, patients were divided into four groups: nonresponders (group A) or responders (group B) to fiber‐ or osmosis‐based laxatives; nonresponders to any medical therapy (group C); and responders to stimulant‐based laxatives (group D). The CI was significantly higher in group A than group B (P < 0.05), with the receiver operating characteristic (ROC) curve analysis showing a CI cut‐off of 21.2 for predicting favorable outcomes of either fiber‐ or osmosis‐based laxatives (P < 0.05). Left/right distribution ratio was significantly lower in group C than group D (P < 0.05), and the ROC curve analysis showed a left/right cut‐off of 0.5 for predicting responders to stimulant‐based laxatives (P < 0.05). CONCLUSION: These findings could help physicians predict favorable outcomes with laxatives without side effects for this patient population.