Bad Milo is a movie about a guy named Ken who has been having some pretty sever stomach problems. He eventually discovers that these problems are due to a demon living inside his colon. Whenever Ken gets angry, or someone wrongs him in some way, the small but completely ferocious demon exits Ken from exactly where you're thinking he would and wreaks havoc.
It sounds incredibly ridiculous, but that's because it is. Bad Milo is to in no way whatsoever be taken seriously. The story is the kind of thing that you'd almost expect to see from Troma or Full Moon Entertainment, and while those movies have their cult followings, things like "Monsturd" don't do a whole lot for me. Milo follows a cookie cutter plot pattern that we've seen a million times before, with only the whole "demon living in his colon" thing to set it apart. I do give it props for pulling a "Teen Wolf" on me though, didn't see that one coming. Still, there's really nothing here you haven't seen plenty of other places.
That's not to say it's bad though, the production value is surprisingly high, and the puppeteering department that handles Milo himself does a fine job of bringing the little guy to life. There are some notable comedic actors, including Ken Marino and a hilarious Patrick Warburton (who ended up being my favorite part of the movie). In fact, most of the cast performs adequately, with only a bit of an over the top showing from Peter Stormare that was a mild annoyance. Even the films score, from composer Ted Masur was a pleasant surprise.
So, at the end of the day, how you feel about Bad Milo will most likely depend on your willingness to sit down and giggle at the silliness on screen. It isn't scary, it isn't gory, it's just a silly little exercise in comedy/horror that directs it's focus mainly on the comedy part. If you can look past the lack of plot, and all the toilet humor, there's fun to be had here.