What Should I Do For A Dog That Has Had Diarrhea For 2 Days? I Have Withheld Food For 24 Hours. She Still Takes Water. No Blood In Stool. Stress Related?

Diarrhea is often mild and self-limiting-usually clears in
2-3 days.  Stress colitis is a common cause of diarrhea in dogs; their gut is their stress organ. 
Diarrhea without loss of appetite, loss of thirst or lethargy is not an
emergency.  Further signs of illness
warrant further attention or again if the diarrhea has not resolved in 2-3
days.

At home treatment includes feeding a bland diet.  As long as your dog is not vomiting food
should not be withheld.  A bland diet can
include boiled chicken or hamburger, boiled rice, or cottage cheese.  Nothing that has spices or flavor--all these
foods are easily digestible.  Add some
plain yogurt--this has Lactobacillus a good pro-biotic for the gut.  Canned pumpkin (non-spiced) has fiber, is
easy on the gut, and helps sweep things through.  I would not feed your dog cheese.

If the diarrhea does not resolve at home contact your
veterinarian for am exam, fecal analysis to screen for bacterial overgrowth,
giardia, and, intestinal parasites.  In middle age and older dogs metabolic concerns can cause GI upset.  Bloodwork will help screen for more serious diseases.

Don't with hold food just try giving her some cooked rice or some oatmeal mix with a little bit of food.and make sure she is drinking water so she don't become dihydrated.if not better in 2-3 days then call the vet back and have her seen.she might have sometime of parasite.

We had the same problem with my sisters dog...she gets diarrhea every two weeks or something like that....her owner is in the military so we are watching her and her brother.  Her brother doesn't have a problem but she does.  If your dog is getting into things and eating things without you noticing it could be causing the diarrhea.  Also the type of food you are feeding her could cause it as well.  Try hamburger and rice...it has worked for her and my dog as well.