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Constipation and Megacolon Casestudy: Can Surgery Save A Cat from Misery?

Reviewed by Missy Beall, DVM, PhD on
Posted February 06, 2014 in Cat Surgery A-Z

Buster, an 8 year old neutered male kitty, came to his family veterinarian after his owner noticed a few piles of vomit on the floor. Over the past few weeks, Buster had been straining to defecate in the litter box. After a physical exam, the vet explained that Buster had severe constipation. Doesn't sound like that big of a problem, right? Actually, this is an all-too-common problem in cats. It sometimes goes unnoticed or untreated, for months to sometimes years. 

You may have noticed that most cats don’t drink much, and their stool is typically harder than dogs’. So it doesn’t take much for a cat to become constipated. Constipation occurs when a pet has difficulty passing stool, and does so in smaller amounts or less frequently than usual. [Editors note: Frequent constipation in cats can be caused by a defect when the muscles of the colon try and contract. Constipation can lead to megacolon if too much waste accumulates.]

Buster’s Doctor discussed the potential need for surgery in the future, but at this stage, it was reasonable to treat him with medications and diet. Buster’s veterinarian administered an enema that helped remove the fecal material under sedation. He sent him home with the following treatment:

  • Lactulose (a stool softener)
  • Cisapride (which stimulates intestinal muscles and helps with elimination)
  • A diet enriched by fiber

Over the next few weeks Buster did well. For the most part, he had normal bowel movements, ate well, and except for the occasional hairball, had no more episodes of vomiting. Soon, Buster’s owners stopped paying close attention to his stool, and when the symptoms started to return they didn't notice right away. 

His appetite decreased slightly, he began having more trouble producing a bowel movement, and he started hiding because his belly hurt. His coat was unkempt, as he stopped grooming. He became dehydrated.  It wasn't until the vomiting returned that his owners realized that something was wrong. They brought him back to the vet. 

Buster had now become “obstipated.” Obstipation occurs when defecation is extremely difficult or impossible.

Abdominal X-rays showed a very large amount of stool backed up in Buster’s colon. The colon was about the size of your forearm. Normally, it should be the size of your thumb, at the most.  

At this stage, the colon was enlarged beyond the point of no return (megacolon). The muscles around the colon

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Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his website at, and follow him at