Gastric emptying speed - DIY test?

[togeprrriii]

Hi all, I would like to know how fast or slow my stomach is moving and how long it takes for the content of my stomac to reach the small intestine. There are medical tests for this, but I need something so do at home.
I was thinking that I could get an idead about the time it takes with a substance that
a. is absorbed into the blood stream only in the small intestine, and that
b. has very immediate and notable effects when it reaches the bloodstream. this would be the signal then that it, or parts of it, have moved from stomach to small intestine.

Any ideas from the community? As I have serious chronic fatigue from an SSRI, I can't try something with strong stimulating effects.

 

[Hiep]

I'm just thinking out loud here...

This may or may not meet your exact criteria but have you considered sprinkling riboflavin (e.g. from a Vitamin B2 capsule) into your food. I don't think you'd need very much: 5-10mg will probably be enough

Then the next time you urinate, if you see the bright yellow colour, you know the riboflavin has made its way into the blood stream and the excess has also been filtered by the kidneys.