Travaglio, Elisabetta, et al. “Prevalence of Constipation in a Tertiary Referral Italian Colorectal Unit”. Annali Italiani Di Chirurgia, vol. 85, no. 3, May 2014, pp. 287-91, https://annaliitalianidichirurgia.it/index.php/aic/article/view/2015.