What Causes White Mucus Discharge During Bowel Movement?

None. I every time I go poop I have white mucus come out. Sometime it stays in my butt until I wipe it out. But also I have pain after I go normally in the upper left side. Also I have been having troubles like if I eat some food or certain foods I puke it up in them sick. This is been happening for a while. I didn t think much of it. About every time now I m having white mucus come in gobs of time looks like like today looked like mold was on the poop. Sometimes the stool looks black but sometimes it looks perfectly normal.