A novel quantitative method via the degree of transverse colon ptosis for chronic constipation assessment

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 The National Natural Science Foundation of China and the Clinical Research Special Fund of Wu Jieping Medical Foundation. Evidence before this study We searched PubMed for papers published between Feb 1, 2000, and Jan 1, 2019, with the keywords “transverse colonic ptosis” OR “abdominal x-ray” AND “constipation” OR “colonic transit”. No restrictions on study type or language were implemented. Our search retrieved studies on the use of stool burden score on AXR in the assessment of constipation but no studies to use transverse colonic ptosis to evaluate colonic transit. Added value of this study We established a Luojia score which was defined as the vertical distance from the splenic flexure to the lowest point of transverse colon on the abdominal x-ray (AXR) that representing the degree of transverse colon ptosis. A retrospective cohort study of 368 patients proved that Luojia score has high sensitivity and specificity in distinguishing slow colonic transit and normal colonic transit as well as obstructed defecation syndrome and normal group. We were satisfied to found that in patients with slow transit constipation, there was a strong correlation between Luojia score and WCS (r=0·618) and a mediate correlation between Luojia score and HADS-A (r=0·507). Implications of all the available evidence Precise assessment and evaluation of colonic transit play an important role in clinical diagnosis and treatment of constipation patients. Our result proved that Luojia Score is a simple and effective assessment system of certain clinic value in in identifying patients with constipation and is a potential predictor of symptom severity. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement 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]. ### Author Declarations All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript. Yes All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data sharing anonymised individual patient data on request or as required by investigators who have been approved by independent review committee about the use of data. Data should not be used beyond the approved proposals A data access agreement signed by requester is needed to gain data. Requests should be sent to the corresponding authors.