Diarrhea is defined medically as the frequent passage of loose or watery stools, representing a deviation from normal gastrointestinal function. This condition often results from an imbalance between fluid intake and absorption in the colon, leading to increased fecal water content. Physiologically, the causes can range from inflammatory processes and infectious agents to alterations in gut motility or bile salt malabsorption. Acute diarrhea is frequently associated with gastrointestinal infections, while chronic forms may be related to dietary intolerances or motility disorders. Management focuses generally on replacing lost electrolytes and maintaining hydration while addressing the underlying physiological cause.