Disgusting colleague!!

I'm having kind of a silly issue at work, but I'm being 100% serious. I work in a very small business, 11-13 employees in on any given day. We have one single stall restroom for the whole office. Very often there is pee on the toilet bowl, and occasionally a glob of something else right in the small area where the actual toilet seat does not cover. I kid you not.

Every Monday we get together and discuss business stuff, project status, etc. Two weeks ago I brought up that we should try to keep the toilet a little cleaner. In an effort to be professional and not get too descriptive, I kept it at that. Then over the week, I noticed there was no change.

I brought it up again at the next meeting, when I was actually asked if we were doing better with our toilet hygiene. I said no, and this time I explained that there is a small area not covered by the toilet seat and this is what needs to be wiped up after you go.

This next day after this meeting, I go to the bathroom and lo and behold, pee droplets all over this area. This time, however, I did notice who came out of the bathroom right before this. Later, I went to the restroom after this person AGAIN and same thing.

This person is a 50-60 year old man, who has a handicap. He can walk, but has a bit of limp. He definitely has less trouble standing up and sitting down than another overweight employee that works with us, so I would not assume that he cannot bend over wipe up his mess. The restroom is basically a handicapped friendly as well, with bars to help you get up and down if needed.

Now that I know who it is, what the heck do I do? I have been wiping it up, using copious amounts of toilet paper, but its really gross and should be kept clean, especially if we have high profile clients in the office, which this person probably wouldn't be to aware of.

As a note as well, there is a small chance that he is doing it on purpose as I am the one bringing up the issue - he is a software developer and I am the UI designer, and maybe he secretly hates what I do and/or has an issue taking instruction from a much younger person. EDIT: Not pulling the sexist card or anything here, there have been some times where he would not listen to or disagree with what I'm explaining to him, and another employee would have to come over and have to help us communicate. However I doubt this is the issue. It may also be a cultural thing for toilet sanitation to be less important, as this person is from a different country.

EDIT: Our crappers are actually very clean, always except for these little pee incidents.