Why do you have to drink barium sulfate before a CT scan?

Drinking barium sulfate before a CT scan is typically done to enhance the visibility of certain areas of the gastrointestinal (GI) tract. Here are the main reasons for its use:

1. Contrast Agent: 
Barium sulfate acts as a contrast agent that absorbs X-rays. When ingested, it coats the lining of the esophagus, stomach, and intestines, which helps to differentiate these structures from surrounding tissues during the imaging process.

2. Improved Imaging Quality: 
By providing a high-contrast outline of the GI tract, barium sulfate allows radiologists to obtain clearer and more detailed images. This can aid in identifying abnormalities such as tumors, inflammation, blockages, or ulcers.

3. Safe and Effective: 
Barium sulfate is generally safe to ingest and is not absorbed into the bloodstream. It passes through the digestive system and is expelled naturally, making it a convenient option for enhancing imaging studies.

4. Specific Conditions: 
It is particularly useful for diagnosing conditions related to the GI tract, including gastrointestinal bleeding, Crohn's disease, and other disorders.

Overall, drinking barium sulfate helps ensure that the CT scan provides accurate and comprehensive information about the patient's GI tract.