IUD pain for a week

Jess
I got the Mirena IUD inserted last Tuesday and I've had severe cramping since then (8 days). I saw a GYN yesterday and my IUD is in place and I don't have any cervix/uterus pain when palpated. Then I was referred to a General Practitioner, who said my pain is coming from my large intestine but because I don't have any other symptoms, its likely not a concern. 
Has anyone else experienced anything similar, or do you have any thoughts?