High-resolution anorectal manometry in children with functional constipation: a single-centre experience before and after treatment - El-Shabrawi, Mortada; Hanafi, Hind M.; Abdelgawad, Manal M.A.H.; Hassanin, Fetouh; Mahfouze, Aml A.A.; Khalil, Ahmed F.M.; Elsawey, Saeed Elsayed (Gastroenterology Review/Przegląd Gastroenterologiczny, 2018)