We mostly cloth, but have some disposables to make outings easier... Unfortunately almost every time we use the disposables, we have a poop blowout, sometimes up the back and sometimes out the legs, which really defeats the purpose. What am I doing wrong? Seems like these things aren't even made to contain poo!

He's 14lbs, normal proportions, I've tried Size 1 and Size 2 and it happens with both.