Any food you eat, no matter if it is a liquid or a solid, begins the digestion process in the same way. The food goes into your mouth, where digestion begins and then into your stomach. From the stomach, it goes into the small intestines where about 90% of the nutrients are absorbed.
Then, the remaining 10% or waste goes into the large intestine where all the water is sucked from liquid food and sent back to the rest of the body for use. All the water in your soup will go back to the body and come out eventually through the excretory system. The indigestible part of your soup will come out from the large intestine.
Soup first goes in through your mouth where the taste is picked up from the tastebuds on your tongue as well as the sense of smell you have in your nose. Together, the taste bud and smell signals go to your brain. Signals are send from your brain to say if you like the taste or not and various other things regarding the soup.
The soup travels into your digestion system where it meets up with all sorts of organs that do their part to filter out the digestible and the waste and to turn it into energy and nutrients for your body to use. What is not used or needed comes out in the flush. How soup is digested also depends on what type of soup it is as some are clear liquids that are easier and faster for your body to digest than a soup with meat or hearty vegetables.