Suggest Treatment For Cramps In Pelvic With Blood In Urine And Stool

I am 23 year old female and I have cramping in my lower pelvic area its pretty severe at times. I went to the doc 2 weeks ago and I'm not prego I have blood in my urine and my xray came back normal. Today I just started having blood in my stools. Any idea what this could be? The doctors seemed stumped last time I went in. Oh and I have the mirena.