Ask Elizabeth: What is There to Treat Idiopathic Megacolon?
Q: For three years, our cat had a chronic problem with constipation. When we realized she had a problem, she was so impacted that the veterinarian had to remove the feces. We then gave her stool softeners, which helped for a while. Later, as the problem worsened, we tried cisapride, but it didn't help. Finally, we resorted to monthly enemas. After about 4 months, even the enemas didn't seem to help. We were told that her condition - megacolon - was hopeless, and that the humane thing to do was to put her to sleep. I made some desperate inquiries and found out about a surgical procedure called a subtotal colectomy that was reported to be effective for cats. We took her to the nearest veterinary college where the surgery was performed the next day; now, 5 months after the surgery, Ebony is healthy and happy. I think it's important for other cat owners to know about this surgery.
A: I am very happy to hear that your kitty is now doing well, and I'd like to provide a little information about the colon disorder called idiopathic (meaning the cause is unknown) megacolon to our readers. Constipation (infrequent or difficult defecation with retention of feces in the colon and/or rectum) is fairly common in cats. If it occurs only occasionally there's usually not much to worry about. However, in some cats, constipation begins to occur more and more frequently, ultimately leading to obstipation: constipation that can't be controlled by medical means. There are many potential causes of obstipation, including congenital megacolon (presumed to be due to developmental abnormalities of the intestinal nervous system) and either congenital, traumatic, or acquired diseases of the bones in the pelvis, but over half result from idiopathic megacolon.
Megacolon with obstipation is most commonly diagnosed in middle aged, male domestic shorthaired, domestic longhaired, and Siamese cats. Cats with mild or moderate forms (or perhaps those with early stages of the disease) often benefit from increased dietary fiber, administration of laxatives or stool softeners of various kinds, and drugs called prokinetic agents (like cisapride) that stimulate the muscles of the colon. As things progress, the occasional enema performed at a veterinary hospital may be necessary. Unfortunately, the need for enemas or other methods of removing feces from the colon often becomes more and more frequent, and ultimately, cats with advanced stages of the disease simply stop responding to medical therapy and the colon becomes little more than a big, flaccid bag containing a mass of hard feces.
If medical management fails, surgical treatment of megacolon is often recommended. A number of surgical procedures have been designed to address a dysfunctional colon, but the current consensus among surgeons is that removal of the majority of the colon, whether it appears grossly diseased or not, is most likely to result in a favorable outcome. This is because judging the health of the feline colon by visual inspection during surgery is very difficult. Subtotal colectomy, the removal of the majority of the colon, is considered the treatment of choice for the surgical management of megacolon that is not responsive to dietary and medical management. This is major surgery, but the overwhelming majority of cats respond quite favorably. The most common postsurgical problem is diarrhea, but most cats begin to form stool of an acceptable quality within several weeks of having this procedure. Life often returns to normal, or near normal, within several weeks. Though a subtotal colectomy is not necessarily a perfect solution, the majority of people whose cats have had one are quite pleased with the results. They continue to share life with a feline friend who, without the surgery, would not have survived.