Dark Stools After ECRP

Hi, I recently went to the hospital for back pain, dark urine and white stools along with yellow tinge in face and eyes, they said I may have a stone blocking my bile duct, they did a cat scan, ultra sound and x-ray along with blood cultures and tested my urine, they said they could see stones in my gall bladder and due to me being a bit bigger they could not get a clear picture, so they assumed it was a stone blocking my bile duct, they put me on an IV with liquid, morphine, antibiotics, I spent 3 days on a liquid diet and on the 4th day I had a ECRP done, they said they seen nothing but a little sludge, the next day the doctor sent my blood away for another test and then released me, my urine was clearing up before they did the test also, but I have been home for 3 days and after getting solids into me my first 2 stools were normal but then 2 were like water but dark dark brown almost black, then they became solid but still very very dark, I am not sure if it is normal or the meds clearing my system but this is the 4th day now and I am starting to think something is going on, if you could please let me know what you think.