Moveable lump at outside bottom left of anus slight discomfort, no bleeding and it's skin coloured quite like a full up skin tag could it be piles?

Could be: What you described is consistent with external piles. It is worth getting it treated as clot formation, bleeding and ulcerations can cause pain and soiling. Have a healthy diet, exercise 30 minutes/day, drink plenty of water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV vaccine.