As a former AFLAC insurance agent I feel slightly qualified to help here

What policy do you have? They pay you directly and you pay the hospital or whatever you want to use the money for. They need a hospital bill or some other form of documentation proving you were in the hospital getting the services. Depending on the plan you have they can pay for quite a bit. Again it goes directly to you NOT the doctor or hospital. It is Supplemental insurance and not
regular insurance. If you need help with co-pays or deductables that is where they come in. If you have AFLAC hospital they will pay (depending on which policy) $400/day for the first 5 days of hospital stay for illness plus $100/day up to 365 days. Both have no lifetime maximum and if seperated by 30 days will pay again as new claims. They will also pay up to $1,000 for the surgery (I don't have the surgical list on hand so I can't say for sure what would be paid for WLS). If you have insurance or even if you are self pay this is a great way to help with the bills. On the website for AFLAC
www.aflac.com/short_term_disability_insurance/default.aspx there is an option on the bottom of the page to look at the brochure for your state in pdf format. It spells it out pretty well there. They cover for Short Term Disability as well - STD and Hospital are the two policies I think I'd recommend. Just realize if you don't have them already they require at least 10 - 12 months before covering a pre-existing condition. They will both also cover pregnacy with the same restriction. All AFLAC policies are portable, which means that if you have it at work and you leave your job for whatever reason you can continue coverage you just have to pay it like a regular bill instead of having it come out of your paycheck.
To answer your question - depending on which policy you have with them they DO cover surgery, hospital stay and time off work. I just realized that the money quoted above is for the state of Maine so the price may be different in your state.
Ask me anything - I'm happy to help. PM me if you have sensitive information.