Do you experience severe pain when having a bowel movement? Like you're passing razor blades? That's a classic symptom of a fissure.
It may also be normal and just the adjustment period. It seems that many new pouchers do just fine in the first days or week at home and then the stuff hits the fan. Most usually it's the new pouch getting used to things.
You might want to try a skin protectant like Calmoseptine, Nupercainal or other product. You can dab a bit up the anal canal. A bidet or sitz bath is also soothing.
You should probably contact your doctor about this because if it's a fissure you would most likely be prescribed something other than pain medications. If it's something like an abscess, you'd want to address that before things get worse.
kathy