Generally when a cat vomits it is a hair ball or they have eaten something that is disagreeing with them, if there no other signs of illness you should take their food and water away for 12 hours and the reintroduce a bland diet, but this has been five day, and there are traces of blood at this point,
When you should call your veterinarian
Vomiting:
• blood in vomit
• vomiting accompanied by diarrhea
• vomit looks and smells like stool
• vomiting is projectile
• vomiting is sporadic and there is no relationship to meals
• multiple bouts of vomiting occur over a short period
• ingestion of a poison (like antifreeze or fertilizer) is suspected
• vomiting persists more than a day or two
• stomach bloating occurs or your cat tries to vomit but can not
• cat also appears listless
• there is weight loss
• showing other signs of illness such as labored breathing or pain
Diarrhea:
• bloody diarrhea
• diarrhea accompanied by vomiting
• multiple bouts of vomiting occur over a short period
• ingestion of a poison is suspected
• fever and other signs of toxicity are present
• diarrhea persists more than a day or two
• cat also appears listless
• there is weight loss
• showing other signs of illness such as labored breathing or pain
For more information please go to Pet Education.com, this is where I have gotten most of the information that is listed here. I hope this is in some way helpful to you. (O: Good luck with your kitty