There were cheers as Michael D and Sabina Higgins left Áras an Uachtaráin which is located in Dublin's Phoenix Park.
President Higgins travelled to hospital in Dublin by arrangement on Sunday and started a course of antibiotics to treat an infection.
President Higgins travelled to St James's Hospital by arrangement on Sunday and received antibiotics.
Concerns have been raised about the unprecedented number of spoiled votes in the presidential poll.
Catherine Connolly, an independent who was backed by the major left-wing parties, pledges to be "an inclusive president for all".
Catherine Connolly arrives at Dublin Castle ahead of official confirmation of her victory.
An overview of the former Presidents of Ireland as the Republic of Ireland prepares to elect a new head of state.
BBC News NI's Dublin Correspondent Gabija Gataveckaite recaps the runners and riders in the Irish presidential election.
Irish citizens living abroad or in Northern Ireland cannot cast a ballot in Friday's election.
