Your cat has been "just a little off" for weeks vomiting now and then, softer stools, a bit less interested in food, maybe some weight loss you only noticed when you picked her up. Nothing dramatic enough to feel like an emergency, but nothing that's going away either. This slow-burn pattern is exactly how many stomach and intestinal problems in cats show up, and it's worth understanding what might really be going on.

Stomach and intestinal problems in cats range widely from inflammatory bowel disease (IBD) and gastritis to ulcers, physical blockages, colitis, and constipation. Many share overlapping signs like vomiting, diarrhea, and weight loss, which is exactly why an accurate diagnosis usually needs bloodwork, imaging, and sometimes endoscopy or biopsy rather than guesswork. Some of these conditions are manageable long-term with diet and medication; others, like a physical blockage, need urgent surgery.

Key Takeaways

• Inflammatory bowel disease (IBD) is a group of conditions causing persistent digestive inflammation without one single known cause, and it's rarely cured outright but it's often well-managed with diet and medication.
• Gastrointestinal ulcers in cats are uncommon and are frequently linked to an underlying tumour, which makes proper diagnosis especially important.
• A gastrointestinal blockage is a genuine emergency cats that swallow string, thread, or other foreign objects need prompt veterinary attention.
• Colitis and constipation are both common and usually treatable, but longterm or recurring cases need a vet's help to find the underlying cause.
• Digestive system cancers are uncommon in cats overall but tend to be aggressive when they occur, especially in older cats.
• Because so many of these conditions share the same symptoms, proper diagnosis not home remedies is what actually determines the right treatment.

Gastritis: Inflammation of the Stomach

Gastritis is one of the more common reasons a cat vomits repeatedly. According to the Merck Veterinary Manual, gastritis is sudden or longterm vomiting caused by inflammation of the stomach. It is caused by eating something that irritates or injures the stomach lining or by infections, parasites, body-wide illnesses, drugs, poisons, immune system dysfunction, or stomach tumors.

The pattern of vomiting itself offers real clues. In cases of short-term gastritis, the vomiting is sudden and may contain evidence of whatever the cat has eaten (such as grass). Bile, froth, fresh blood, or digested blood that looks like coffee grounds may be seen. Long-term cases look different: longterm vomiting is usually intermittent and may be associated with weakness, lethargy, weight loss, dehydration, and electrolyte imbalance. There are also two specific, named subtypes worth knowing: lymphocytic-plasmacytic gastritis and eosinophilic gastritis are types of longterm gastritis that involve the movement of immune cells into the tissues of the stomach.

Diagnosis and treatment: the diagnosis is typically made by evaluating the cat's history, a physical examination, and response to treatment. Blood, urine, and fecal tests may be necessary, along with x-rays and/or an abdominal ultrasound. Visualizing the stomach with a long, flexible scope (endoscopy) and evaluating tissue samples may be necessary in cats that have longterm gastritis. For the specific immune-driven forms, cats with lymphocytic-plasmacytic or eosinophilic gastritis may require medications to suppress the immune system. The outlook depends on the cause of the vomiting and the likelihood of correcting the underlying disorder.

Inflammatory Bowel Disease (IBD)

IBD is one of the most commonly diagnosed chronic digestive conditions in cats, and it's genuinely a group of related conditions rather than one single disease. Inflammatory bowel disease is actually a group of digestive system diseases that are recognized by certain persistent signs and by the presence of inflammation without a known cause. The various forms of inflammatory bowel disease are classified by their location in the body and the type of cell that is involved. Lymphocytic-plasmacytic enteritis and eosinophilic enteritis are the most common types in cats.

Who gets it, and what it looks like: inflammatory bowel disease appears to affect all ages, sexes, and breeds, although it may be more common in purebred cats. The average age reported for the development of disease in cats is 7 years. Signs are often longterm and sometimes come and go. Vomiting, diarrhea, changes in appetite, and weight loss may be seen.

A connection worth knowing about: in cats, there is an association between inflammatory liver disease, pancreatitis, and IBD. This combination of inflammatory disorders is often referred to as triaditis. This is exactly why a cat diagnosed with IBD may need broader monitoring of the liver and pancreas too, not just the intestines. There's also an association between severe IBD and intestinal tumors, which is part of why ongoing monitoring matters even once a cat seems stable.

Why diagnosis takes time: inflammatory bowel disease can be difficult to diagnose, because many of its signs can be seen in other diseases as well. Veterinarians often use blood, urine, and fecal tests to rule out other diseases and to identify complications, such as low levels of protein or electrolytes. An abdominal ultrasound may help to identify abnormal sections of the digestive tract. A definitive answer usually needs tissue: tissue biopsies obtained with an endoscope or surgery are necessary for the diagnosis of IBD.

Treatment is about management, not usually a cure. The goals of treatment are to reduce diarrhea and vomiting, promote appetite and weight gain, and decrease intestinal inflammation. If a cause can be identified (such as diet, parasites, bacterial overgrowth, or drug reaction), it should be eliminated. Diet plays a central role: your veterinarian may recommend feeding your cat a hypoallergenic or elimination diet. This means feeding a source of protein that the cat has not previously eaten... this diet should be the sole source of food for a minimum of 4 to 6 weeks, and no treats of any kind should be fed unless approved by your veterinarian. Medication is often layered on top: glucocorticoids, which suppress the immune system, are among the drugs most often used in the management of inflammatory bowel disease. Antiparasitic drugs, certain antibiotics, vitamin supplementation, immunosuppressants, or other anti-inflammatory drugs may also be recommended.

Being upfront about the long game matters here: although feline inflammatory bowel disease can often be controlled with an appropriate combination of diet and medication, the condition is rarely cured. Relapses may occur.

Gastrointestinal Ulcers

Ulcers are less commonly diagnosed in cats than in dogs or people, and when they do occur, there's often more going on underneath. Gastrointestinal ulcers are wounds in the stomach or intestinal lining caused by stomach acid or digestive enzymes. They are uncommon in cats. Gastrointestinal ulceration is often associated with tumors in cats, but the cause can also be unknown.

Signs can be deceptively quiet. Cats with stomach ulceration may have no signs and may develop sudden, life-threatening bleeding within the digestive tract. In other cases, they can have a history that includes vomiting, sometimes with blood, and abdominal discomfort that may appear less severe after a meal. Watch for dark, tarry stools, which indicate the presence of blood, and pale gums suggesting anemia both are signals that shouldn't be dismissed.

Diagnosis and treatment: blood tests, abdominal ultrasound scans or x-rays may be used. To confirm the diagnosis, endoscopy and biopsy of the stomach and intestines are often recommended. Because of the underlying risk, hospitalization with intensive care is often needed because of the high risk of severe bleeding. Medication directed at the ulcer itself reduces stomach acidity, prevents further destruction of the stomach lining, and promotes ulcer healing. In general, treatment should be continued for 6 to 8 weeks.

The outlook hinges almost entirely on the cause. The outlook for cats with ulcers that are not caused by malignant tumors is good. Outlook is guarded to poor for those with ulcers caused by tumorswhich is exactly why finding out what's actually behind an ulcer matters so much more than simply treating the symptom.

Gastrointestinal Obstruction: When It's a Blockage

This is the condition that turns a digestive problem into a genuine emergency. Gastrointestinal obstruction is the blockage of the digestive tract. The blockage can arise outside, within the wall, or inside the cavity of the digestive tract. An obstruction interferes with the passage of food and fluids, can damage digestive tissues, and can result in life-threatening consequences.

Blockages can happen at different points, and the causes vary. Obstruction of food movement out of the stomach can result from tumors, foreign objects, polyps, and overgrowth of stomach tissue. Further down, intestinal obstruction may be partial or complete and may be caused by foreign objects, intussusception (a condition in which the intestine telescopes on itself), incarceration (such as being constricted in a hernia), and tumors.

One specific risk deserves its own mention. Long, thin foreign objects (such as string, yarn, or fabric) may become attached at the base of the tongue. If the object is long enough to trail into the intestines, normal intestinal movement tends to cause a sawing or cutting motion on the gut, leading to intestinal perforation and abdominal infection. This is precisely why a cat that's played with string, thread, or ribbon and is now drooling, vomiting, or off their food needs urgent veterinary attention waiting to see if it "passes on its own" can be dangerous.

Signs to watch for: signs of gastric or small-intestinal obstruction vary but often include vomiting and loss of appetite. Other signs include lethargy, diarrhea, abdominal pain or swelling, fever or subnormal body temperature, dehydration, and shock.

What your vet needs to know: access to string or sewing needles or missing objects (such as toys) may be important facts and should be reported. Diagnosis typically involves abdominal palpation, abdominal x-rays, ultrasonography or examination using an endoscope, along with blood tests to check for complications.

Treatment often means surgery. An endoscope can be used to remove some objects from the stomach. If an obstruction cannot be removed using the endoscope or if it occurs in the intestines, then surgery will be needed. The encouraging news: many of these animals recover well as long as they are diagnosed and treated quickly timing is genuinely the deciding factor here.

Colitis: Inflammation of the Large Intestine

Colitis affects the colon specifically, and it tends to have a distinctive symptom pattern. Cats with chronic colitis tend to be middle-aged and are often purebred. In most cases, the cause is unknown; bacterial, parasitic, traumatic, kidney-related, and allergic causes are suspected.

Recognising it: cats with inflammation of the colon have a history of straining to defecate and frequent passage of mucus-laden feces, sometimes containing bright red blood. Feces are often of a small volume and a more liquid consistency. Weight loss and vomiting are uncommon a helpful distinguishing feature from small-intestinal disease, where weight loss and vomiting are more typical.

Treatment often starts with diet. Cats with some types of inflammation may respond to dietary management alone (such as changing to lamb and rice, or a commercially available diet), sometimes with an antibiotic or anti-inflammatory medication added to speed things along. Longterm colitis is likely to improve initially, but signs frequently recur. Most cats with inflammatory bowel disease will need some form of longterm treatment.

Constipation and Megacolon

Constipation is genuinely common, and most cases resolve without drama — but chronic cases can become something more serious. Constipation is the infrequent or difficult passage of feces. The fecal material is often dry and hard. It is a common problem in cats. Severe, unrelieved constipation has its own name: obstipation is severe constipation with a mass of dry, hard feces that does not pass.

What causes it: obstruction is the most common cause and is due to the cat's inability to pass poorly digestible, often firm matter (such as hair, bones, or litter) that has become mixed with fecal material. Dry, hard feces can also occur due to insufficient water intake or reluctance to defecate (for example, because of a dirty litter box, guarding of the litter box by another household cat, or painful defecation). Left unaddressed long enough, some cats with longterm constipation or obstipation may develop megacolon, an enlarged intestine caused by a defect in the muscle strength of the colon.

Treatment scales with severity: mild constipation can often be treated by switching to a high-fiber diet, keeping your cat from eating bones or other objects, providing ready access to water, improving opportunities for defecation, and using appropriate laxatives. One safety note is worth repeating clearly: laxatives formulated for human use can be very dangerous for pets only ever use what your vet specifically prescribes. In more severe cases, a veterinarian will need to remove retained feces using enemas or manual extraction while your pet is under general anesthesia. Cats with chronic constipation or megacolon that have been unresponsive to medical treatment may respond to removal of the affected section of the large intestine.

Malabsorption

This is a less commonly discussed but genuinely important cause of ongoing weight loss. Malabsorption is poor absorption of a nutrient resulting from interference with its digestion, absorption, or both, and most cases of absorption failure are caused by diseases in the small intestine, including several conditions already covered on this list.

What it looks like: signs typically include longterm diarrhea, weight loss, and altered appetite. However, diarrhea may be absent even when disease is severe. Weight loss may be substantial despite a good appetite a genuinely important detail, since a cat eating normally and still losing weight is easy to dismiss but shouldn't be.

Diagnosis and outlook: the diagnosis is confirmed by taking biopsies of intestinal tissue by surgery or with an endoscope. The outlook for malabsorption is good if there is a simple solution (such as exocrine pancreatic insufficiency). However, the outlook worsens for cats with severe disease of the small intestine.

Cancers of the Digestive System

Digestive cancer is genuinely uncommon in cats, but it's worth understanding what raises the risk. Cancer of the digestive system is uncommon and represents less than 10% of all cancers in cats. When it does occur, it most commonly develops in the small intestine. Older animals are predisposed, occurring with an average age of 10 to 12 years in cats. Siamese cats have an increased risk for some types of intestinal cancer.

There's a specific viral link worth knowing: alimentary lymphoma in cats is believed to be caused by the feline leukemia virus, even in cats that test negative for the virus. Intestinal tumors in cats tend to spread rapidly and are usually malignant. Lymphoma and adenocarcinoma are two common types of digestive system tumors seen in cats.

Signs and outlook: vomiting (sometimes with blood), diarrhea (also with blood), loss of appetite, weight loss, and lethargy are the most common signs, and cats with intestinal tumors may also have signs of anemia, such as pale gums. Treatment involves surgical removal and/or chemotherapy, depending on the type of tumor, and the outlook can vary from excellent to poor, depending on the specific type of tumor and whether all of it can be removed. Malignant tumors usually have a poor prognosis with survival times of less than 6 months.

Signs That Point to a Stomach or Intestinal Problem

Because these conditions overlap so heavily, the overall pattern matters more than any single symptom:

• Vomiting, whether sudden or ongoing
• Diarrhea, especially with blood or mucus
• Straining to defecate, or hard, dry stools
• Weight loss, even with a normal appetite
• Reduced appetite or reluctance to eat
• Lethargy or general dullness
• Abdominal pain, swelling, or discomfort after eating
• Pale gums (a sign of possible anemia or blood loss)
• Dark, tarry stools (a sign of digested blood)

How Vets Approach Diagnosis

Given how many conditions share the same symptoms, your vet will typically start broad and narrow down. Blood, urine, and fecal tests rule out systemic disease and parasites. Abdominal x-rays and ultrasound help identify structural problems like blockages, thickened bowel loops, or organ changes. Endoscopy allows direct visualization of the stomach and intestinal lining, often with biopsy in the same procedure and for several of these conditions, a tissue biopsy is genuinely the only way to reach a definitive diagnosis rather than an educated guess.

FAQ

My cat has had loose stools on and off for months but seems otherwise fine — should I still see a vet?
Yes. Long-term or recurring digestive symptoms, even mild ones, are worth investigating rather than watching indefinitely. Conditions like IBD and colitis often show up exactly this way persistent but not dramatic and earlier diagnosis generally means easier management.

Is IBD in cats curable?
Not usually, but it's often very manageable. With the right combination of diet (often an elimination or hypoallergenic diet) and medication, many cats with IBD live comfortably long-term, though relapses can occur and ongoing management is typically needed.

My cat swallowed a piece of string how urgent is this really?
Very urgent. String and similar linear objects can anchor at the base of the tongue while trailing into the intestines, and normal gut movement can cause the string to cut through the intestinal wall. Don't wait to see if it passes this needs same-day veterinary attention.

Can I give my constipated cat a human laxative?
No, never without your vet's specific direction. Laxatives made for human use can be genuinely dangerous for cats. If your cat is constipated, ask your vet about safe options and appropriate diet or hydration changes instead.

My cat is eating normally but still losing weight what could that mean?
This combination a good appetite with ongoing weight loss can point to malabsorption or another underlying digestive condition, since a cat can absorb nutrients poorly even while eating enough. It's worth a vet visit with bloodwork and possibly imaging to investigate further, rather than assuming everything is fine because the appetite looks normal.

References

1. Defarges, Alice; Blois, Shauna; Hall, Edward J.; Gibson, Thomas W. G.; Mitchell, Kelly D. "Disorders of the Stomach and Intestines in Cats." Merck Veterinary Manual, Full Review Aug 2018, Last updated Aug 2025. https://www.merckvetmanual.com/cat-owners/digestive-disorders-of-cats/disorders-of-the-stomach-and-intestines-in-cats