LAUSR

ABSTRACT Objectives: Ileo-colonoscopy (IC) can be technically challenging because of unpredictable colonoscope loop formation. Aims of this study were to assess the risk of loop formation and to attempt to understand which factors were likely to predispose to which subtype of loop. Methods: Prospective study conducted on children referred for an IC at Sheffield Children's Hospital. Presence and type of loop was objectively assessed using the magnetic endoscope imaging tool. Results: Three hundred procedures were prospectively evaluated. Only 9% of paediatric ICs were loop-free. Alpha loops were the most common loop in children older than 5, whereas reverse alpha loops and a wider variety of complex and repetitive loops were observed in younger patients. Once a specific type of loop has formed, the risk of re-looping in a different way or in a different position of the colon is reduced. Left lateral starting position was found to increase the risk of reverse alpha loops and re-looping. Challenging loops, such as reverse alpha, were more frequent in males. Higher body mass index (BMI) was associated with an increased risk of alpha and deep transverse loops formation, while lower BMI with a higher incidence of reverse alpha and N loop. Loop formation did not prevent 100% ileal intubation. Conclusions: This study represents the first attempt to describe loop formation according to patient characteristics in a large paediatric series. Further studies are needed in order to establish if these findings could be helpful in simplifying the execution of IC procedures in children and facilitate the learning curve during endoscopy training programs.