Background/Aims: To assess the effectiveness and feasibility of a brief session of hypnosis to reduce distress in children with functional constipationundergoing anorectal manometry (ARM). Methods: A partially-blinded randomized controlled pilot trial was conducted in children 4-18 years old scheduled for ARM. Children were randomized to receive a brief session of hypnosis prior to ARM or standard care. Non-blinded and blinded observers rated the child’s level of distress using the Observation Scale of Behavioral Distress and a 4-point-Likert scale, respectively. Differences between groupswere analyzed using Fisher’s exact test or Mann-Whitney U test as appropriate. Results: Data from 32 children (15 hypnosis and 17 standard care) were analyzed. Prior to insertion of the catheter, the observed mean levels of distress were lower in the hypnosis group according to both the non-blinded observer (median 0.0 [interquartile range {IQR} 0.0-0.3] vs 1.4 [IQR 0.3-2.4]; P = 0.009) and the blinded observer (median 0.0 [IQR 0.0-0.0] vs 0.5 [IQR 0.0-1.0]; P = 0.044). During ARM, observed and reported levels of distress did not differ significantly. In the hypnosis group, 92.9% of parents and childrenreported that hypnosis helped the child to relax. There were no significant differences in resting pressure, squeeze pressure, or duration of the procedure between both groups. Conclusion A brief session of hypnosis for children before ARM is an easily incorporable intervention that lowers distress levels prior to theprocedure and is positively perceived by children and parents.