Keywords: سدیم هیدروژن; Diarrhea; Pathophysiology; Management; ATPase; adenosine triphosphatase; cAMP; cyclic adenosine monophosphate; Cg; chromogranin; cGMP; cyclic guanosine monophosphate; ENaC; epithelial sodium channel; 5-HT; 5-hydroxytryptamine; FODMAP; fermentable oligosac