It depends on the symptoms and severity. Obviously you don't want to wait too long if nothing is improving no matter what you do. I normally go in when I am dehydrated, sleeping most of the day, unable to eat anything, the obvious weight loss that follows, and when I am losing a lot of blood. Generally when the medication is doing nothing...
If you're worried about the pain and it is something that you're having a really hard time with then don't hesitate to ask for pain killers. They obviously aren't permanent and you can let your doctor know that you understand they are on an 'as needed' basis but that you DO need them. As for the D, I'm not sure how much of a problem it is for you so I can't say too much except maybe try half a tablet of imodium, see if it helps, and increase as needed. Of course I would ask a GI about this first as well if you can.
Ultimately, if you feel that things are bad enough and can't improve at home then I say definitely go to the ER. They can at least hook you up on some intravenous fluids and maybe give you something to calm down the BM's.
I hope you feel better soon!!
20 years old, Diagnosed with moderate to severe Crohn's and Colitis in May of 2008.
Prednisone 20 mg, pentasa 2 pills 4x a day, bentyl as needed, omeprazole in the morning, multivitamin, humira every other week, and good probiotics.
Surgery for ectopic pregnancy most likely the result of severe Crohn's inflammation in July of 2008.
Attempting a diet without refined sugars, high fat content, bleached or bromated flour, most dairy, red meat, and avoiding anything spicy like the plague. Also refuse to eat anything with trans fat or high fructose/corn syrup.
"He who has a why to live for can bear with almost any how."