IF begins it action as soon as it leaves the stomach and enters the small intestine. This is usually within 20-90 minutes depending on what is eaten. In the small intestine is acts to accelerate motility which for many of us it causes spasms and pain quickly. You are fortunate you don't have this problem. For some of us it is a real nuisance Have a great day!
-------------------- STABLE: ♂, IBS-D 50+ years - Science of IBS