The blood circulation system in the human body is pressurised and the pressure is regulated by various systems.
Is there a similar pressure system operating in the alimentary canal? What is it called and what are the facts? Whats the value of the pressure and what are the safe limits?
No.
The alimentary canal is basically a tube open at both ends (humans are topologically equivalent to doughnuts!)
Yes, it has pinch points and valves, but it’s not a sealed system.
As stated, there is no digestive pressure as an analog to blood pressure. Blood moves through the system under pressure created by the pumping of the heart. Food is not moving by a central pump. Food moves through the digestive system through peristalsis, muscular contractions throughout the intestines that move food through it in waves.
I have gastro-esphogeal reflux disease, AKA GERD. Which means that the top of my stomach doesn’t close. If my GI tract were pressurized, I’d be spewing vomit all the time.