Your dog could have a serious and life threatening problem. He should be taken to a vet as soon as is possible, as online or telephone diagnoses can be quite unreliable due to the often complex nature of medical problems - especially in animals! A full physical examination by your veterinarian will determine the cause of your dog's problem and he/she will also be able to provide you with appropriate medication. Until you can get your dog to a vet, ensure it drinks plenty of water as vomiting and diarrhoea can lead to dehydration, which is not only harmful and dangerous in itself, but also detrimental to your dog's ability to heal and recover - things it is definitely trying to do if it is sick!
With that said, one of the most common causes for a dog to be vomiting yellow bile and having diarrhoea is IBS, or irritable bowel syndrome. An endoscopy by your vet will be able to determine if this is indeed the cause, and your dog will most likely be treated with prednisone and put on a special diet to help its bowels calm down. You should consider your dog's lifestyle, and try to recall if it may have ingested anything suspect within the last few days that could cause an upset stomach or food poisoning. Sometimes even a shard change in diet or emotional circumstances in the home can cause a dog to get sick and exhibit the symptoms you are seeing. Write down anything you can think of, and take the information to the vet with you as soon as you can.
With that said, one of the most common causes for a dog to be vomiting yellow bile and having diarrhoea is IBS, or irritable bowel syndrome. An endoscopy by your vet will be able to determine if this is indeed the cause, and your dog will most likely be treated with prednisone and put on a special diet to help its bowels calm down. You should consider your dog's lifestyle, and try to recall if it may have ingested anything suspect within the last few days that could cause an upset stomach or food poisoning. Sometimes even a shard change in diet or emotional circumstances in the home can cause a dog to get sick and exhibit the symptoms you are seeing. Write down anything you can think of, and take the information to the vet with you as soon as you can.