What Causes Swelling And Pain In Buttock Along With Constipation?

Hi about three days ago i woke up to realise i was constipated i have been using lactulose and its helps a little but now my right butt cheek hurts. And my butt crack has all swollen up do you know what this could be? Ps. This is causing me unbearable pain the swelling has almost doubled since i first noticed it.