WOW! I learned some new tips from reading the other mom's advice, below!
What I wanted to add is that old rule which is:
HOT water to remove poop, and
COLD water to remove blood (Hot water SETS a blood stain forever).
THE SOONER THE BETTER!
Never let it sit if you can help it, but get it right away. If you do have to wait, then the HOT water STILL helps to remove it quicker, with the other agents added helping even more. I have found any kind of detergent, hand soap, with hydrogen peroxide, etc helps to speed it up, as long as you use hot water with it. But now I will try the others, too! Thanks for asking - It helps ALL of us!!!