4 year old potty training, HELP PLEASE!?

My son is 4 yrs old and has been fully potty trained for over a year now. He doesn't even wet the bed at night! But, this past month we have had some problems with him. He is going into the bathroom and pooping everywhere. This has happened 5 times now. He gets it on the floor, wall, himself, and even smears it on the toilet with his hands. Every time I have had to scrub the entire bathroom and him. This is making me crazy. I feel like he is to old for this and wonder if this is just being spiteful or an accident. But I mean how many "accidents" can one child have! Like I said he has been fully potty trained for the last year with NO accidents. I just don't know what to do from here. Has anyone else ever had this problem? Any advice on what to do or even why he would do this? Thanks so much