Which agent may be administered to reduce bowel gas during ultrasound examination?

Which agent may be administered to reduce bowel gas during ultrasound examination?

• A. Metoclopramide
• B. Ondansetron
• C. Simethicone
• D. Buspirone

Answer: (C)

Reducing bowel gas helps ultrasound waves penetrate and create a clearer image. Simethicone acts as an anti-foaming agent in the gastrointestinal tract, lowering the surface tension of gas bubbles so they coalesce into larger bubbles that are easier to pass or evacuate. By decreasing small gas bubbles, it reduces screen artifacts and improves the acoustic window for abdominal imaging. It’s not absorbed and is used orally before the exam to help visualization. The other agents shown don’t specifically target gas in the bowel: metoclopramide is a prokinetic antiemetic that speeds gastric emptying, ondansetron is an antiemetic that blocks serotonin receptors, and buspirone is an anxiolytic. None are used primarily to reduce bowel gas for ultrasound.

Reducing bowel gas helps ultrasound waves penetrate and create a clearer image. Simethicone acts as an anti-foaming agent in the gastrointestinal tract, lowering the surface tension of gas bubbles so they coalesce into larger bubbles that are easier to pass or evacuate. By decreasing small gas bubbles, it reduces screen artifacts and improves the acoustic window for abdominal imaging. It’s not absorbed and is used orally before the exam to help visualization.

The other agents shown don’t specifically target gas in the bowel: metoclopramide is a prokinetic antiemetic that speeds gastric emptying, ondansetron is an antiemetic that blocks serotonin receptors, and buspirone is an anxiolytic. None are used primarily to reduce bowel gas for ultrasound.