Luojia Score: A New Quantitative Option for Evaluating Precise Colonic Transit and Symptom Severity of Constipation

BACKGROUND: Assessment of colonic transit tend to be more subjective and qualitative. This study aimed to evaluate the capability of our new quantitative scale to predict the subtypes of constipation and assess symptom severity of patients with slow transit constipation. METHODS: A retrospective cohort population was assembled, consisting of adult patients with chronic constipation who underwent both colonic transit test and defecography between 2012 and 2019. Radiological parameters were measured on AXRs. The Luojia score was introduced to convey the vertical distance from the splenic flexure to the lowest point of the transverse colon, representing the degree of transverse colon ptosis. Patients with slow transit constipation only were especially required to complete the Wexner Constipation Scale (WCS) and Hospital Anxiety and Depression Scale (HADS) for clinical severity assessment. FINDINGS: Of 368 patients, 191 patients (51·9%) showed slow colonic transit, and patients with slow colonic transit were more likely to have severe ptosis of the transverse colon on AXRs. Patients with slow colonic transit had a significantly higher Luojia score than those with normal colonic transit (p˂0·001). A cut-off of 195 mm was used to distinguish slow colonic transit. A significant difference in Luojia score was also found between patients with obstructed defecation syndrome and normal patients, and a cut-off of 140 mm was identified. In patients with slow transit constipation, there was a strong correlation between Luojia score and WCS (r=0·618) and a moderate correlation between Luojia score and HADS-Anxiety (r=0·507). These results indicated that the Luojia score is a reliable predictor of symptom severity and psychological condition in patients with slow transit constipation. INTERPRETATION: The Luojia score might be a new quantitative, precise method in the assessment of constipation. FUNDING: This project was funded by grants from the National Natural Science Foundation of China [No. 81570492], the National Natural Science Foundation of China [No. 81500505] and the Clinical Research Special Fund of Wu Jieping Medical Foundation [No. 320.6750.18467]. DECLARATION OF INTERESTS: CJ reports grants from Clinical Center of Intestinal and Colorectal Diseases of Hubei Province, Colorectal and Anal Disease Research Center in the Medical School of Wuhan University, Quality Control Center of Colorectal and Anal Surgery in the Health Commission of Hubei Province, the National Natural Science Foundation of China, during the conduct of the study. QQ reports grant from and the Clinical Research Special Fund of Wu Jieping Medical Foundation. All authors declare that they have no financial or personal relationship which could present a potential conflict of interests ETHICS APPROVAL STATEMENT: This study was approved by the medical ethics committee of Zhongnan Hospital of Wuhan University.