sad Mastiff puppy

The signs of inflammation in the colon (also called the large intestine) are the same regardless of the cause: mucousy diarrhea, straining to pass stool, cramping, and sometimes a surprising urgency to "go". These symptoms can be acute, as is common with short-term stress like boarding, returning from boarding, or diet change, or they can be chronic, as with whipworm infection or inflammatory bowel disease.

Many people get confused between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). IBD is a physical disease in which the intestinal lining is infiltrated by inflammatory cells. The delicate intestinal lining becomes thickened, altering the absorption of nutrients. The infiltration can be seen under the microscope, which is how the diagnosis is confirmed. Inflammatory Bowel Disease is a completely different disease from Irritable Bowel Syndrome, so if you are looking for information on Inflammatory Bowel Disease, please click the link above.

IBS is a psychosomatic disease. It is the activity of the mind that causes the symptoms. Most people have had some kind of experience where stress has produced 
intestinal distress, be it cramping, nausea, diarrhea or all of the above. The medical definition of IBS for humans includes at least three days of abdominal pain per month 
for at least three months.

Chronic anxiety can similarly result in chronic diarrhea. This is basically what IBS is all about. Intestinal biopsy results are normal because there is nothing directly wrong with the large intestine. The process is the same whether the patient is human or non-human.

Large intestinal diarrhea in veterinary patients can have many causes, and IBS is afoot in about 10-15% of cases. It is important to rule out physical causes before blaming psychological reasons.

Still, if all tests are normal and treatment for physical problems is not yielding results, this is when a biopsy is helpful. If after medication trials, diet trials, and diagnostic tests, including biopsy, are all normal, then it is time to consider IBS.

It should be noted that fresh blood in the diarrhea is common with large intestinal diarrheas but not so much with the large intestinal diarrhea of IBS. Fresh blood in the diarrhea is a sign of a physical cause, not a psychosomatic cause. Knowing this can help direct the medical approach.

Treatment of IBS

IBS is most commonly addressed via the GI tract rather than the psyche. Increasing dietary fiber is helpful to many IBS patients, as fiber has been found to help normalize the spasms of the large intestinal muscles, and many therapeutic high-fiber diets are sold through veterinary hospitals. If your pet finds these unpalatable, ask your veterinarian about how to add wheat bran or a commercial fiber supplement to a diet your pet prefers. There are presently several commercial dog foods that contain calming supplements. Using one of these, plus a fiber supplement, might cover both the fiber angle and the anxiety.

IBS can be managed either through the GI tract or through the psyche. Some effective human remedies have not been evaluated for animals, but others have been: 

Insoluble Fiber

Fiber can be either insoluble (meaning it doesn't dissolve in water) or soluble (meaning it does dissolve in water). Soluble fiber becomes a gel in the GI tract and feeds the bacteria (acting as a "prebiotic") in the colon, whereas insoluble fiber draws water into the colon to make a softer stool. Only insoluble fiber has been found helpful in human IBS. There are several veterinary diets combining both soluble and insoluble fiber. 

Probiotics

Probiotics are live cultures of "helpful" bacteria that one takes orally. These bacteria populate the intestine, producing helpful biochemicals and consuming harmful biochemicals. They do not permanently populate the GI tract, so after they are no longer consumed, they have no lasting effects. There are many veterinary probiotics available, but it is best to check with your veterinarian about which one to use. A probiotic is a live culture with an emphasis on the word "live." The bacteria must live in the package on a shelf and must be able to survive the acid of the stomach and travel to the correct area of the GI tract. Many products are marketed that are not able to accomplish any of this.

Anxiety Management

A number of supplements have recently been marketed to address anxiety (not to mention pheromone products). These are not as strong as prescription drugs but are available without prescription for those who wish to try them:

Alpha Casozepine: This is a milk protein with natural calming properties. It is available as an oral supplement (Zylkene^®) for pets or in special calming pet foods (Royal Canin Calm Diet^®, Hills Urinary Stress C/d for Cats^®).

L-Theanine: This is a derivative of green tea and is available in capsules and flavored chews (Anxitane^®, Solliquin^®, Composure^®).

Adaptil Defuser and Collars: Dog Appeasement Pheromone, or D.A.P., is naturally secreted by mother dogs to communicate safety and security to her litter of puppies. This pheromone has been synthesized and is available as a room spray, plug-in wall defuser, and impregnated collar that the dog can wear. This gives the anxious dog a message in their own language that there is nothing to be anxious about.

Cannabinoids: These are controversial and are not presently legal except as hemp products, which may be appropriate. CBD is commonly marketed for pets, but at present, none of the recent legalization efforts have included pet products, and quality control is lacking.

A more aggressive approach might be addressing the anxiety with medications. The source of emotional stress may not be obvious. Still, general anti-anxiety medications such as amitriptyline, clomipramine, or fluoxetine may be of use, particularly if the anxiety source is not clear or cannot be removed. Some patients will respond to supplements as listed above. It is important to imagine the pet’s world from their perspective. Your pet does not speak English and must infer what is happening directly from events they witness. Inconsistent scheduling, moving to a new home, noisy construction nearby, or weather changes can confuse an animal.

Consult your veterinarian if you wish to pursue one of these therapies. However, keep in mind that IBS is not diagnosed until a medical workup for physical causes of large bowel diarrhea has not shown any reason for illness.