Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Inflammatory bowel disease (IBD) in cats is chronic inflammation of the stomach or intestines. It causes ongoing vomiting, diarrhea, weight loss, or poor appetite. Many cats improve with a diet change alone, and others need anti-inflammatory medication such as prednisolone. IBD can look very similar to low-grade intestinal lymphoma, a common cancer in older cats, so biopsies are sometimes needed to tell them apart. Vitamin B12 is often low and should be checked and supplemented.
Signs
- Vomiting more than occasionally, including hairballs more often
- Diarrhea or soft stool
- Weight loss, sometimes despite a good appetite
- Poor or changing appetite
- Lethargy or a scruffy coat
Frequent vomiting isn’t normal for cats, even if it’s “just hairballs.”
Diagnosis
- Bloodwork, urinalysis, and thyroid level (hyperthyroidism causes similar signs)
- Stool tests and deworming
- Vitamin B12 (cobalamin) and folate levels
- Abdominal ultrasound to look at the intestinal walls and lymph nodes
- Diet trial
- Biopsies by endoscopy or surgery if signs continue, to distinguish IBD from lymphoma
Treatment
Diet
A hydrolyzed-protein or novel-protein diet, fed strictly, often improves signs within 2 weeks. Some cats need only this.
Vitamin B12
Cats with IBD often have low B12, which can worsen signs. Supplementation by injection or tablets is simple and helpful.
Medications
- Prednisolone: the main anti-inflammatory drug, tapered to the lowest effective dose
- Budesonide: a steroid that acts mainly in the gut
- Other immune-suppressing drugs, such as chlorambucil, in some cats (see chlorambucil for cats and dogs)
- Anti-nausea medication and appetite support
- Probiotics as an add-on
IBD vs. intestinal lymphoma
Low-grade (small cell) intestinal lymphoma is common in older cats and causes the same signs. It’s often treated with prednisolone plus chlorambucil, and many cats do well for years. Biopsies with special testing are needed to tell the two apart.
Related conditions
Some cats with IBD also have inflammation of the pancreas and liver (“triaditis”). Your vet may check for these if your cat has jaundice or abdominal pain.
Home care
- Feed only the prescribed diet, including treats.
- Keep a log of vomiting, stools, appetite, and weight.
- Give medications consistently, and never stop steroids suddenly.
- Follow pills with water or a treat to protect the esophagus.
When to call your vet
Call if your cat stops eating for more than a day, vomits repeatedly, has blood in vomit or stool, or loses weight quickly.
What to avoid
- Frequent diet switching.
- Human anti-diarrhea medicines, such as Pepto-Bismol, which is unsafe for cats.
- Letting a cat go without food, which risks fatty liver disease.
Frequently asked questions
Can IBD in cats be cured?
It’s usually managed long term rather than cured, but many cats live normal lives.
Is IBD painful for cats?
It can cause discomfort, nausea, and cramping. Treatment usually helps.
Sources
- Jergens AE. Feline idiopathic inflammatory bowel disease: what we know and what remains to be unraveled. J Feline Med Surg. 2012
- Marsilio S. Differentiating inflammatory bowel disease from alimentary lymphoma in cats: does it matter? Vet Clin North Am Small Anim Pract. 2021
- Merck Veterinary Manual: Inflammatory bowel disease in small animals
- Cornell Feline Health Center: Inflammatory bowel disease
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.