Your charkas are always spinning, but willfully focusing on them and spinning them faster causes them to vibrate at a higher rate, helping to activate them and increase your power ectra.
The solar charka is related to things like willpower and is of the element of fire. It rules over digestion, the stomach and so on. Naturally having a healthy and strong solar charka will be good for your stomach, however if you have any heath issues with any part or organ of the body you can do a meditation to target and heal that area more specifically.
You should spin and clean all your charkas daily regardless but as well as that for example, you can go outside and sit in the sun and breathe in solar energy into your stomach and visualize it glowing with a powerful white-gold light, and as you do so affirm something like "I am breathing in powerful white-gold solar energy, in a safe and healthy way this energy is completely and totally healing my stomach."
This is just an example, for further information on the topic of healing visit
https://www.templeofzeus.org/Healing.html