摘要Objectives To explore the value of performing a modified colonic transit test in the diagnosis of chronic constipation. Methods we retrospectively analyzed the results in 101 patients admitted to the MDT Outpatient Clinic of Subei People's Hospital, Jiangsu Province, China, from July 1, 2019, to July 31, 2021. Patients were prohibited from using drugs and stimulant foods that could affect bowel motility for three days before and during the examination. We performed two abdominal X-rays at 6 and 72 hours after oral ingestion of the barium suspension to observe the residual condition of barium in the patient's colon. We then gave specific treatments based on the different types of constipation detected in the patients. Results Compared with patients with normal transit, patients with slow transit (P < 0.001) and patients with rectal evacuation disorders had a significantly reduced stool frequency (P < 0.05). The kappa coefficient of the modified colonic transit test compared to anorectal manometry in the diagnosis of functional defecation disorders (FDDs) was 0.649, indicating substantial consistency between the two methods. Conclusion The modified colonic transit test not only assesses colonic transit function and provides an initial determination of the type of constipation, but also shows the colon morphology, providing a reference for possible subsequent treatments.