Which class of medication should be avoided in the management of fecal impaction due to constipation?

• A. Laxatives
• B. Antacids
• C. Antihistamines
• D. Opiates

Answer: (D)

In fecal impaction, the goal is to restore regular stool passage, which means avoiding anything that slows gut movement or dries stools. Opioids slow intestinal propulsion by activating mu receptors in the gut, leading to reduced peristalsis and more water absorption. The result is harder, drier stool that is harder to pass, which directly worsens an existing impaction. Therefore, opioids should be avoided during management, and alternative analgesia considered while disimpaction and bowel regimen are pursued.

Laxatives are used to treat impaction by increasing stool softness and promoting transit. Antacids and antihistamines can contribute to constipation as a side effect, but they do not address the underlying need to relieve an impaction and are not appropriate primary therapies in this situation.