Interesting idea - I'll see if there's a way we could implement this. We've definitely tried to align ourselves with building an effective program, if you pay through the website and don't see an improvement in symptoms after the program, you can get a full refund.
Here are some studies on IBS using hypnotherapy: - https://onlinelibrary.wiley.com/doi/full/10.1111/apt.13706 (the study we're based off) - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1773844/ (5 year effects showed) - https://pubmed.ncbi.nlm.nih.gov/25736234/ (1000 patients, 76% responding) - https://pubmed.ncbi.nlm.nih.gov/24840368/ (meta analysis of IBS hypnotherapy studies)
In terms of how hypnotherapy works for IBS, the exact mechanism isn't known. It's been shown to help with reducing visceral hypersensitivity and improving intestinal motility, thought to be due to utilising the gut-brain connection.
And for pain management: - https://www.semanticscholar.org/paper/Controlled-trial-of-hy... (fibromalgia) - https://pubmed.ncbi.nlm.nih.gov/16025734/ (disability related pain) - https://pubmed.ncbi.nlm.nih.gov/19459087/ (low-back pain)
There's also more research into other areas including: erectile disfunction, exam anxiety, depression, etc.
The harder part with a double blind study is developing the placebo side, since from a patients perspective it's very easy to know if you're getting the psychological treatment (hypnotherapy) or not. It's possible using a sham treatment or something similar, or using a waitlist or active control.
Very specific cases was what I meant. Focusing on those for which there is evidence.
The subscription model however seems counterproductive - the business side wants to continue subscriptions as long as possible while the stated goal is to solve a problem thus minimizing subscriptions. I wonder if a 'pay it forward' model would work. So that if it was effective for you, you could pay for a month of a stranger's subscription.