A retrospective cohort study on oesophageal food bolus obstruction in the North Denmark region in 2021-two thirds were never diagnosed with a cause.

"Declarations Ethics approval and consent to participateThe Scientific Ethics Committee for Region North Jutland evaluated the project as not being in need of ethical approval and informed consent within Danish law [21]. The study was performed in accordance with the Declaration of Helsinki and regulations in the declaration. All hospitals approved the project as a quality study (Number 2017–011259). Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding The study was funded by Marie Pedersen and Jensine Heiberg’s Foundation, Center for Clinical Research, North Regional Hospital Hjørring, Denmark. The funding was used for language revision and publication fee."