I don't know what was meant by pearls along the intestines. It could be related to this, but could be artifact and not significant. Your vet can answer that tomorrow (Monday).
Right now, I am trying to make sure that she is OK to wait until tomorrow
Has she had only one bloody stool? If more, how many
Was it fresh red blood or black?
How large was it?
Was there mucous in it (globby??)?
Is she vomiting or have any other signs of a problem?
Could she have gotten into rodent poison?
A simple way to check for good circulation (perfusion) is to look at the gums. They should be pink, not white, gray or bright red. Then press on the gum over or slightly behind an upper canine tooth. This pushes the blood out. When you remove your finger from the gum, the color should return to pink in a bit less than 2 seconds. If it is 3 seconds or more, the circulation/perfusion is decreased.
If the BM contained red blood and mucous, it indicates colon inflammation (colitis). Usually, the BMs are small and frequent. There are a number of causes and includes parasites particularly whipworm. Take a stool sample with you when you go to the vet.