Join the Facebook Community
Never assume you know what people want, even if you were that person. Because you're a practitioner, your viewpoint may be different.
Join a few Facebook groups where people have the problem you want to solve.
Survey them!
Ask: What is the number one symptom you wish you could get rid of?
What if they say something general, like bloating? If you create a problem, on something like bloating, you would want your target audience to share common symptoms or issues so that you can still build a program that will work for most.
For example: Say I love helping people with Bloating and I want my target audience to be those with SIBO. I could talk about not being able to eat FODMAPs in a lot of my content and on the sales page. You want people to agree that they have that problem and that you have the solution to the problem.