I agree with the last comment - I would also buy "stool softener" at the drugstore - it doesn't have a dramatic effect as a typical laxative - nor will it send you running to the bathroom, but it will make things pass easier.
I would check with the doctor though - just to make sure everything is ok - I'm sure they could prescribe medicine that will be a little more quick acting than over the counter stuff.
Im not a doctor but have had similar to you. Your butt rash can last a life time if you use the wrong anti itch creams like mycolog cream as will destroy the senitive tissues around your butt. Also scratching that area with dirty fingers makes infection very possible. There is a lot of bacteria under your finger nails. To relieve the itching buy some of the 1% topical cortizone cream (not oitment) its over the counter. The inner herorrhoid probably started the itching as was bleeding and most likely get infected.
Your very young to have these and suggest changing to a high fiber diet or will only get worse over the years.