This happens to me on occasion. There is a valve attached to the flush mechanism that leaks and drips down on the floor. I thought it was a leak between the toilet and the floor, but it wasn't. If you have a foot flush unit, there is a plastic cap that goes over the top of the valve. remove the cover and examine the plumbing with a flashlight. If its the valve, you should be able to see it dripping or feel that it's wet.
I've replaced three of them over time in my unit. Camping world sells the replacement valve for about $20. I keep a spare with me now so when the next leak occurs, I don't have to make a special trip to pick one up.
It's fairly simple to replace. Two hose clamps and two screws.
2016 Ford F350 Turbo Diesel SRW 4x4
2017 Grand Design Reflection 297RSTS
2013 Ford F350 Turbo Diesel SRW 4x4 (Destroyed by fire - 8/29/16)
2014 Grand Design Reflection 337RLS (Destroyed by fire - 8/29/16)