Which option best matches the standard definition of diarrhea?

• A. Abdominal pain with constipation
• B. Increased stool water content
• C. Stool color change
• D. Passage of loose or watery stools at least three times in 24 hours

Answer: (D)

Diarrhea is defined by both how liquid the stool is and how often it occurs. The standard criterion is passing loose or watery stools three or more times within a 24-hour period, which reflects increased stool liquidity and increased frequency. The other descriptions don’t fit the definition: abdominal pain with constipation points to constipation, not diarrhea; merely increased stool water content notes liquidity without frequency; and changes in stool color are not part of the diagnostic definition of diarrhea.