I contacted the seller and asked more information about usage of ECR and veterinarian treatments here is her reply:
This product works so much better than the oil method, there is no need to do it. I don’t think the oil would interfere with ECR as much as the pain killers would. Although banamine has been given with ECR and ECR still works. Some vet give a lot of muscle relaxer type pain killers and this stop the muscles from working (muscle relaxant), thus interfering with ECR. ECR gets the muscles in the intestines moving, therefore you would not want to give a lot of pain killers.
Apparently this can work as soon as 10 minutes to hear gut sounds and would definitely be something that could be used while the vet is coming, and sometimes they are not available right away. There is a You Tube video about this too if you google Equine Colic Relief that shows a horse with colic and having ECR administered to it.
I am excited about this product, but hope I never have to use it, even though I have ordered it.