What Causes Painless Lump On The Vagina?

Hi I am 28years old with 2 children,i weigh 110pounds, i first noticed a growth at the entrance after havin my first baby, the doctor slit the vagina and stiched it. Since having my second baby i noticed even more (ball shaped) growth. I would like to know what could be the cause and what is the best treatment if theire is any . Thank you