When i poop there is white slimy lookingstuff on it and today there was a big white chunk on the end of it what is it?

Mucus in stool: You may have a bacterial or protozoan infection caused by small worms in your stool. These are easy to get [pinworms] that are transmitted through young children in day care or kindergarten. I suggest speaking with your doctor and bringing in stool specimens to diagnose whether you have this condition. You also may have an inflammatory condition of the intestines. Seek medical attention