Does Your Dog Have Irritable Bowel Syndrome or Inflammatory Bowel Disease?

Your dog has intermittent bouts of diarrhea and vomiting and alternates between straining to defecate and having a sudden urge to defecate. Additionally, she is experiencing abdominal discomfort (rumbly tummy and flatulence) and a concomitant loss of appetite. Does she have irritable bowel syndrome (IBS) or irritable bowel disease (IBD)?

It can be confusing because the symptoms of the two conditions have a lot of overlap, and their names sound similar. But they are very different illnesses with different causes — and different remedies. Here’s the skinny.

Definitions

IBS is a psychosomatic illness, meaning there is nothing wrong with the digestive system per se and the brain (“psycho”) is causing physical issues (“somatic”) elsewhere in the body. It’s usually chronic stress or anxiety in a dog’s day-to-day life that leads to the glitches in the GI tract that can make a dog so uncomfortable. Often, her diarrhea when she is in the throes of a bout of IBS (the symptoms can come and go) will have a mucusy consistency.

We should note that technically speaking, IBS is nomenclature used solely for people. In dogs, the correct term is stress diarrhea or stress colitis. “Colitis” refers to inflammation of the colon, also known as the large intestine. That is essentially where the condition plays out (and explains why the diarrhea is mucoid).

IBD is a strictly physiological condition in which the lining of the small or large intestine becomes inflamed because of an invasion of inflammatory cells. Sometimes other parts of the GI tract, particularly the stomach, may also be subject to inflammation. It’s an allergic-like reaction. Possible causes include harmful bacteria in the gut or a poor reaction to a specific protein in the diet, but often the culprit remains unknown. What is known is that dogs with IBD have a compromised ability to digest the nutrients in their food and absorb them for proper use by the body’s tissues. A dog can end up losing significant weight.

Diagnosis

IBS (stress colitis) is a diagnosis of exclusion; there is no specific test for it. A veterinarian will start by conducting a number of screenings to see what might be causing the ongoing symptoms. These may include a stool culture, imaging via x-ray or ultrasound, analysis of the blood and urine, and perhaps even an intestinal biopsy. If everything checks out — the dog has normal intestinal cells and all other diagnostic testing comes up empty — a case of IBS may be deduced. This is especially true if a conversation with the vet yields information about changes in the dog’s environment that could cause stress.

IBD can be diagnosed at times with imaging such as ultrasound and conclusively diagnosed with a tissue biopsy. Sometimes the biopsy does not require a full exploratory surgery. Depending on the suspected location of the inflammation, an endoscopy might suffice to get a cell sample that can then be examined under a microscope. If the pathologist working to make a determina​tion finds an abnormal level of immune cells in the tissue of the gut, IBD can be confirmed. It is an overreaction of the immune system that causes the inflammation.

Treatment

IBS (stress colitis) can sometimes be mitigated with antispasmodic drugs or with more fiber in the diet, which can potentially help to reduce diarrhea. But the most effective treatment is to address the source of your dog’s stress and try to ameliorate it. Sometimes it’s hard to figure out why a dog has become so anxious. But if changes to your pet’s routine have preceded the symptoms — perhaps a move to a new house or the addition of another person to the household — you can make sure to give your dog lots of attention and reassurance, along with lots of play time that will get her mind on other things and help settle her nerves. In some cases, a drug such as fluoxetine (Prozac) may be in order.

IBD most often has to be treated with a number of different approaches because it is idiopathic — meaning an exact underlying cause usually cannot be found. These approaches include dietary changes like adding a new protein to the dog’s food or more fiber, medications (such as antibiotics) that may have an anti-inflammatory effect on a dog’s GI tract, and perhaps probiotic supplements to possibly restore balance to the flora of the gut. Immunosuppressants such as corticosteroids may be prescribed as well. Different dogs are going to respond to different treatments.

Prognosis

IBS (stress colitis) has a very good prognosis when tended to properly. The problem essentially resolves. But because dogs with the condition “wear” their stress on their guts, take note if your pet starts having bouts of diarrhea or flatulence again or a noisy stomach. You may need to calm things down in the home or change her medi-
cation protocol.

IBD also has a good prognosis — as long as the dog has a good response to the treatment up front. While it can’t be cured, many dogs can go on to lead good lives with the right diet and medication. And sometimes their drug dosages can even be reduced.