Driven to the end of my tether just 2-3 weeks ago I have elected to go on a stomach & gut reset diet. Many people have heard of the 5/2 diet where you have two days every week just drink and thus no food, and indeed many people have, I think, had positive experiences and some have built it or something similar into their lifestyle. My diet choice starts off in a very similar way, that is just liquids.
After the first two days my diet goes in a very different direction. It concentrates on paying attention to your body, listening for changes. For instance I can play back (in my mind) exactly my bowel movements in the last week and can describe in detail what they felt like. It is this attention to detail about my body that helps me understand when foods are helping or hindering progress, and by how much. It also helps me pick out subtle differences that may depend on quantities or other foods combined during cooking.