What does a green stool along with lower back pain kidney area mean?

Well I have been experiencing lower back pain in my kidney area as of around 10:30 today and then I just had a bowel movement and it was green. My lower left back area started all of a sudden and was so bad I was doubled over and crying. The earliest I can get into the doctor's is tomorrow (10/10/08). The doctor says that most likely the kidney pain is from a UTI (Urinary Tract Infection) or Kidney infection/stones. The green bowels is most likely from change in diet eating to much candy, or post-nasal drip can also cause slightly green bowels. Some infections can cause both or the symptoms could be unconnected. If you are really worried consult a doctor. By the way I am a 16 year old White female. 5 foot 9 and about 110 pounds. I am consulting my doctor because the pain is horrible. I suggest you talk to a doctor and not look to the internet for answers. Believe it or not doctor's do actually have a clue what they are talking about.