I just went to the doctor and found out I have a fissure tract in my ?

I have had this for two years and this is basically a opening ...like a open sore that just wont heal. He thinks I may have croahns disease. He wants me to get blood tests, cat scan and a colonoscopy not fun. Has anyone ever had this and has it ever healed on its own? i have be dealing with this for 2 yrs