Bloody stools

Question
I have a 7-year-old, who defecated in the tub today(Saturday) and a bloody,cloudy mess came out of her.  The blood that came out was extremely dark, and the last time she defecated normally was Thursday.  I took her to my veterinarian in a panic within the hour of the defecation.  She advised me there appeared to be no blockage, but the iguana's color was darker but her temperament was normal.  She asked me to wait till Monday and drive her two hours to the nearest veterinarian that's expertise is reptiles.  I am going on Monday regardless, but I can't help but wonder what the problem could be right now.

Answer
Hi Lauree,
Did the vet x ray her?  If not, then that should be done for sure.
Are you sure it was blood and not dark urates? Dehydration can cause dark urates.. When you go to the vets on Monday, I would ask for x ray and blood work.  The x ray to see if there is something that may have scraped her..will also show size of organs.  The bloodwork will should if there is a problem with kidneys, liver, etc... Also, I would have a fecal check done for internal parasites..
What is her normal diet?
Has she ever laid eggs before?
I would give her a nice long, warm soak...and offer her water from a syringe to make sure she is well hydrated.
If she happens to have the same "mess" she had today, I would put it in a plastic bag and take it to the vets with you.
Dark is generally a sign of stress....going to the vet is stressful.
Here are links to finding a vet that is able to treat reptiles.Please do let me know how it goes.
http://www.herpvetconnection.com

http://www.arav.org/ECOMARAV/timssnet/amm/tnt_mdsearch.cfm

http://www.anapsid.org/vets/