overflowing toilet

My brother has a 10-year-old low flow toilet that periodically (not consistently) "clogs" with just urine in it and then overflows causing water damage to the floor below. Once when I was visiting him this happened to me with lots of water all over the floor. Is the only solution to replace the whole toilet? Or are there some adjustments I can make to the flushing mechanisms? I'm somewhat familiar with the workings of toilelts, but I am at a loss as to how to fix this.

Thanks,

Desperate (Ralph)

Sounds like there may be a restriction/clog in the drain line. Unless the previous heavy load never made it clear, just flushing liquid should never cause it to overflow. My unprofessinal opinion. Now, most companies 10-year old low-flow toilets were lousy (as some still are!), so it didn't take much to clog them. SOrry, this doesn't help much.