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Digestive disorders are not uncommon in cats, ranging from mild symptoms that improve without treatment to more severe conditions. Find out more about common causes, signs and treatments of digestive problems in cats in our guide.

Signs and symptoms of digestive issues in cats

If your cat has digestive issues, it may show up as one of these symptoms or a combination of signs including:

  • changed appetite. Their appetite may be increased or decreased with digestive disorders, but it can also be a sign of a range of other health conditions
  • change in behaviour. You may see your cat appearing lethargic, wanting to hide more or playing less often
  • weight loss. Unless on a diet, any changes in their eating habits resulting in weight loss should be investigated. Read more about underweight cats
  • regurgitation or vomiting. Vomiting may happen if your cat consumes inappropriate food, after eating grass or ingesting fur causing hairballs. However, it could also be a sign of a more serious illness. Read more about vomiting in cats
  • constipation. They may be straining and struggling to poo, or only producing small amounts of stool which is often dry and firm
  • diarrhoea. Depending on the health concern your cat has, they could experience passing large or small amounts of diarrhoea, consistency ranging from soft to watery

If you notice any of these signs or something else wrong with your cat, make an appointment with your vet straight away so they can check them over.

Causes of digestive problems in cats

There can be many reasons for digestion problems in cats, here are some of the most common causes:


Many cats can be sensitive to sudden changes in their diet or if they consume food that is not designed for cats (for example, human foods or excessive treats). This can result in diarrhoea, and more occasionally vomiting or constipation.

Food or ingredient intolerances, or allergies can contribute to your cat experiencing the symptoms. Lactose intolerance (a reaction to dairy products) can lead to diarrhoea, so it is recommended to not give milk to cats. 

Infectious diseases

Infectious diseases such as viruses, bacteria and parasites are a common causes of digestive issues, especially in young cats. If your cat has an infection, it can in many cases cause symptoms such as vomiting, diarrhoea and weight loss.

Inflammatory bowel disease (IBD)

Inflammation of the stomach, small intestine and/or large intestine leads to poor absorption of nutrients and can cause weight loss, change in appetite, vomiting or diarrhoea.

Although the exact cause of IBD is frequently unknown, factors such as changes in the intestinal microorganisms, a cat's unique immune system, food allergies and stress may also play a role.

Liver or kidney disease

Both the liver and kidney work to remove toxins from the body. If your cat has a liver or kidney disease, it can cause their body to build up toxins leading to loss of appetite, vomiting and diarrhoea.

The liver and possibly kidneys may be affected by the same inflammation that causes inflammatory bowel disease.

Many cats suffer from kidney disease as they get older and this can lead to dehydration. Dehydration in turn can cause constipation. Find out more about kidney disease in cats.

Pancreatic disease

Inflammation of the pancreas, called pancreatitis, is not uncommon in cats and is frequently found alongside inflammatory bowel disease and liver inflammation (this condition is known as triaditis). It can range from mild and grumbling to very severe and can cause signs of loss of appetite, weight loss, pain, diarrhoea and vomiting.


Several cancers can affect the digestive system, causing signs of digestive disorders. The most common is called lymphoma.

Symptoms often include vomiting (with or without blood), diarrhoea (sometimes with blood), loss of appetite, weight loss and lethargy. Find out more about cancer in cats.

Intestinal blockages

While most cats are cautious about eating unknown items, some may accidentally ingest them while exploring or playing.

Small objects may pass through your cat’s system without causing an issue, but some can get stuck causing a gastrointestinal blockage.

Because of cats’ love for chasing string and thread, if ingested these can cause a particular type of obstruction called a ‘linear foreign body’.

Blockages need to be treated as an emergency. You should contact your vet as soon as possible if you know your cat has ingested something they shouldn’t have or is presenting with symptoms such as loss of appetite, vomiting, abdominal pain, straining or failure to pass any stools and lethargy. 


Pain around the hips or spine, as it’s commonly seen with arthritis in older cats, can contribute to constipation as they can delay passing stools.

Cats who have had pelvic injuries may have a narrowing which can prevent them from passing faeces normally and can cause constipation. 

Inappropriate toileting site

Cats are quite choosy about where they toilet. If the toileting site is not ideal, it may delay them going to the toilet which can lead to toileting outside of the tray and could contribute to constipation.

Things preventing cats from wanting to use the litter box include finding it difficult to reach, cat litter being unfamiliar or uncomfortable, and feeling stressed by other pets or noisy environments. Read more about cats and toileting.

Diagnosing cat digestion problems

Diagnosing the underlying reason can take some time and require several tests. Your vet will ask about the history of symptoms, perform a physical examination and may consider some of the following:

  • analysis of samples of faeces
  • blood and urine tests
  • dietary trial, to assess your cat’s response to different foods
  • further tests as necessary; x-rays, ultrasound examination and/or endoscopy under general anaesthesia

Treatment for cat digestive problems

Treatment will depend on the underlying cause, your cat’s age and any other health issues. It may include one or more of the following:

  • dietary management
  • supplements and medication such as probiotics, antibiotics or anti-inflammatory treatment
  • fluid therapy, for dehydration and electrolyte replacement
  • surgery, may be needed to remove a foreign body
  • stress management; reducing stress and ensuring easy access to clean, comfortable and well-located litter tray

Home remedies for cats with stomach issues

If you notice your cat has vomiting, diarrhoea or constipation, their behaviour changes or something else seems to be wrong, don’t delay contacting your vet for an appointment. 

For cats that have a history of digestive issues, or if you’re looking for ways to maintain your cat’s healthy digestive system, try the following:

  • avoid feeding any leftover or human foods. Most cats are lactose intolerant and should not be given any dairy products. Foods such as chocolate, onion and garlic are also toxic to cats
  • maintain a well-balanced diet and avoid overfeeding your cat. For cats that have sensitive stomachs, a specialist or prescription food may be helpful, ask your vet for advice. If you have to change their diet, do it gradually. Find out more about feeding your cat in our guide
  • incorporate probiotic cat supplements. There are many products to choose from, so your vet is the best first point of contact to recommend the right supplement for your cat's condition
  • use a pheromone diffuser like Feliway if your cat gets stressed and make sure to provide plenty of enrichment at home. Food enrichment activities can be particularly helpful for those cats that eat too quickly resulting in vomiting
  • increase their water intake. Feeding moisture-rich wet food can help prevent dehydration and support better digestion. Check out our tips to encourage your cat to drink more
  • groom regularly, may be helpful for the management of excessive hairballs. Find out more about grooming your cat

What to do if my cat has diarrhoea? 

Sometimes a cat has diarrhoea but seems otherwise fine. In this case, it could be a temporary issue potentially caused by a sudden change in their diet or something they have eaten causing a sudden upset stomach. 

If this happens, ensure they have access to plenty of fresh water and either feed their usual food in small amounts and more regularly or consider a bland diet such as plain boiled chicken.

If your cat still has diarrhoea for longer than a day or two, or it is accompanied by other signs such as lethargy, lack of appetite, vomiting or if the stool is black or has blood, contact your vet for an emergency appointment.

What should healthy cat poo look like?

When you go to clean your cat’s litter box, paying attention to what their stool looks like can be a good indicator of any potential health problems. 

Healthy cat poo should be well-formed, moist and easy to scoop. Certain changes in consistency such as soft or very hard and dry, or white, green or black in colour need to be investigated.

Fluctuations in your cat’s poo can be normal and are often influenced by their diet and hydration. However, any persistent changes such as frequency of toileting or stool appearance can indicate your cat has a digestive problem or other health-related issue and they need to be seen by a vet.

Why is there blood in my cat’s poo?

Finding blood or red streaks in your cat’s faeces can be alarming. While it may be caused by underlying health conditions such as infections, inflammation, parasites or rarely cancer, it can also be due to your cat having constipation and straining. Very dark or black faeces can be a sign of bleeding in the small intestines. 

If you see any of these signs, don’t delay and contact your vet for an appointment to assess your cat. 

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