Mice lacking Muc2 (Van der Sluis et al, 2006), Agr2 (Park et al, 2009; Zhao et al, 2010) or having mutations in Muc2 that interfere with initial mucin folding and assembly (Heazlewood et al, 2008) develop spontaneous colitis or display rectal prolapse. This evidence concerns the gene MUC5AC and Rectal prolapse.