Has your cat been diagnosed with colitis? Does your cat occasionally vomit or have diarrhea? Have you been to the veterinarian more than once for these problems? Colitis in cats is a common problem, and if your cat struggles with chronic diarrhea and/or vomiting, then inflammatory bowel disease, or IBD in cats, could be the culprit.
IBD is described as a chronic inflammatory condition of the gut, and it's one of the causes of colitis in cats. IBD can affect different parts of the gastrointestinal tract, and the location determines what the disease is called. If it affects the stomach it, is called gastritis; if it affects the small intestines, it is called enteritis; and if it affects the colon, it is called colitis. In IBD, inflammatory cells infiltrate the walls of the intestines and interfere with normal digestion. The cause of IBD in cats is still unknown, but it is postulated that IBD in cats is the result of a complex interaction among diet, the immune system and the microbiome — which is the bacterial population in the gut.
How Is IBD in Cats Different From IBS?

IBD is considered an autoimmune condition and differs from stress colitis in cats, which is sometimes called irritable bowel syndrome (IBS). IBD results from inflammation in the gut and can arise from a number of conditions that may be associated with autoimmune problems. In contrast, IBS results from stress and often causes a spastic colon that produces diarrhea. IBS is controlled by stress management, while IBD is managed by nutritional therapy and medication.
What are the Symptoms of IBD in Cats?
Signs of IBD in companion animals include diarrhea, weight loss, vomiting, lethargy and/or changes in appetite. IBD in cats often manifests as increased appetite and large amounts of diarrhea. However, a cat might also experience a decreased appetite in which weight loss is common.
How Is IBD in Cats Diagnosed?
IBD is first determined through exclusion, which means that other causes of vomiting and diarrhea are first ruled out. Your vet will likely ask for your permission to run laboratory tests, including blood work, urine analysis, fecal analysis, and a gastrointestinal panel. These tests are intended to rule out many diseases that can have the same symptoms as those of IBD, such as chronic pancreatitis, intestinal parasites, food responsive enteropathies, intestinal dysbiosis, etc.
If all these tests come back negative, then it's time to examine the intestines themselves. Your vet may recommend an abdominal ultrasound and/or a biopsy of the small intestine. A biopsy is the only way to definitively diagnose IBD; follow your vet's recommendations for additional testing.