Which assessment finding would indicate that diphenoxylate is effectively reducing diarrhea?

• A. Reported decrease in abdominal pain
• B. No evidence of blood in stool
• C. Increase in bowel sounds
• D. Decreased number of bowel movements

Answer: (D)

Diphenoxylate works by slowing intestinal motility, giving the gut more time to absorb water and electrolytes. When it’s effectively controlling diarrhea, the most telling sign is a decrease in the number of bowel movements—the stool becomes more formed as transit time increases. Abdominal pain can vary and isn’t a direct measure of diarrhea control, the absence of blood in stool indicates no bleeding but doesn’t quantify diarrhea reduction, and an increase in bowel sounds would reflect more, not less, gut activity. So the decreased number of bowel movements best shows the medication’s effectiveness.