The Meckel’s diverticulum is located on the jejunum and marks the beginning of the ileum. Its absorption starts during the embryonic stage and ends after birth, and lasts as a remnant of the yolk sac. It is part of the lymphoid tissue associated to the gastrointestinal tract and carries out extramedullary mielopoiesis between weeks 2 and 7. It contains B cells and macrophages. Failure in its complete absorption can be related to infectious processes in the embryonic stage.