Retrograde colon imaging through colonic transendoscopic enteral tubing helps to confirm the cause of difficult colonoscopy: a case report.

Numerous factors can contribute to a difficult colonoscopy, potentially leading to an incomplete procedure and overlooked lesions. Alternative strategies for handling difficult and incomplete colonoscopies should be considered. We present the case of an 85-year-old male who underwent a difficult colonoscopy, during which two expert endoscopists spent 1.5 h attempting various techniques but failed to intubate the cecum. Subsequently, colonic transendoscopic enteral tubing (TET) was performed. Abdominal plain film revealed tortuosity of the TET tube in the left abdomen corresponding to the distribution of the descending colon. Retrograde colon imaging was conducted by injecting a mixture of contrast medium and air into the colon via the TET tube. X-ray demonstrated well-developed visualization of the entire colon and terminal ileum. And evident elongation and tortuosity of the descending colon resembled an N-type folding pattern. The final diagnosis was determined as descending colon redundancy. Colonic TET combined with retrograde colon imaging through the TET tube may serve as an effective supplementary approach for identifying causes of difficult colonoscopy and improving diagnostic accuracy for bowel diseases when complete visualization is not achieved.