This document provides guidelines from the World Gastroenterology Organisation on the diagnosis and treatment of acute diarrhea. It discusses the global epidemiology and impact of acute diarrhea. It also reviews the major causative agents of acute diarrhea including bacteria (such as E. coli, Campylobacter, Shigella, Vibrio cholerae, Salmonella), viruses (such as rotavirus, norovirus, adenovirus), and parasites (such as Cryptosporidium, Giardia). It provides details on the clinical manifestations and diagnosis of acute diarrhea and recommends treatment options based on the severity of dehydration and the likely causative agent. The guidelines are intended to provide a global perspective on acute diarrhea in