Final answer:
Barium sulfate is selected over iodinated contrast media for patients who may have a perforated bowel because it's very insoluble, reduces the risk of irritation and allergic reactions, and provides greater visual detail on X-rays without being absorbed into body tissues.
Step-by-step explanation:
Barium sulfate oral contrast media would be selected instead of iodinated oral contrast media because the trauma patient may have a perforated bowel. Barium sulfate is a suspension of a chalky powder that coats the lining of the patient's intestinal tract without being absorbed due to its very low solubility, which is represented by a solubility product (Ksp) of 2.3 × 10⁻⁸. It provides greater visual detail on an X-ray as it makes the barium-coated areas appear white. This characteristic is particularly important in cases of suspected bowel perforation, as barium sulfate is less likely to cause irritation or allergic reactions if it leaks into the abdominal cavity compared to iodinated contrast. Also, since barium sulfate is very insoluble, it won't be absorbed into the body's tissues, making it a safer alternative. Medical imaging using barium sulfate can help diagnose conditions such as acid reflux disease, Crohn's disease, and ulcers.