Although the etiology of these multifactorial disorders is complex as it includes a combination of genetic, immunological, environmental and gut microbial factors (Shouval and Rufo, 2017; Zhang et al., 2017), both a significant contribution of electrolyte malabsorption to IBD associated diarrhea (Binder, 2009; Priyamvada et al., 2015; Magalhães et al., 2016) and a considerable share of NHE3 therein is beyond all question (Siddique et al., 2009; Sullivan et al., 2009; Yeruva et al., 2010; Lenzen et al., 2012; Anbazhagan et al., 2018). This evidence concerns the gene SLC9A3 and irritable bowel syndrome.