As for IBD patients, the decreased abundances of Faecalibacterium and Fusicatenibacter, which respectively promote the production of butyrate and IL-10, have been repeatedly demonstrated as significant alterations of gut microbiome [28,29,30]; however, little is known about the underlying pathophysiology in patients with quiescent IBD suffering IBS-D-like symptoms, and it may be quite different from that in IBS patients without IBD. This evidence concerns the gene IL10 and irritable bowel syndrome.