We recommend consulting your veterinarian if vomiting or diarrhea occurs. When a cat vomits, contractions of the muscles of the stomach and abdominal wall produce a pressure buildup that propels the contents of the cat's stomach back up the esophagus and forcibly out of its mouth. Vomiting is distinct from regurgitating - a passive process whereby the cat gags out the undigested food, mucus, or saliva without involving the muscles of the stomach and abdomen. Regurgitation occurs usually, but not necessarily, soon after eating. Diarrhea is loose, watery stool with an accompanying increase in the amount of stool and the number of bowel movements.
Most healthy cats pass well-formed stools once or twice a day.
The seriousness of digestive upsets varies, depending on the cause, the age of the cat, and its overall health. If you have a cat that tends to eat very rapidly and large amounts of food in record time, try feeding the eager eater separately from other household cats so it's not competing for food. While cats sometimes bring dietary discomfort upon themselves, owners, too, can cause their cats' dietary-related upsets. For example, a sudden switch from one cat food to another can result in a bout of diarrhea. We recommend introducing new food into your cat's regular diet a little bit at a time, making a gradual switch over a period of a couple of weeks.