If you mean bum as anus, then yes it is hemorrhoid. If you don't have much discomfort , follow these instructions before it gets worse.
Eat fruits, salads, drink atleast 6 glasses of water, drink metamucil, do enema with fleet bottle gently for easy BM. Fill fleet bottle with luke warm water. After enema lie on bed for 5 mins before BM. It will go away in 2- 3 weeks.
If you won't take care of it right away, it will be very painful and then you may have to go through surgery. Recovery from surgery is also painful will take 10 days of bed rest.