A subtotal colectomy — removing most of the colon — costs roughly $3,000 to $6,500 for a cat, including stabilisation, surgery and several days in hospital.
Most owners reading this are tired. Their cat has been in and out for enemas for a year, the lactulose has stopped working, and someone has finally suggested removing the colon.
First, the urgent thing
A cat straining in the litter tray may be constipated, or may be unable to pass urine. They look identical — the same posture, the same crying, the same repeated trips.
One can wait until morning. The other kills within about 24 to 48 hours.
If you cannot be certain which you are looking at, treat it as an emergency. See our guide to urethral obstruction in cats.
What megacolon is
The colon is a muscular tube that moves faeces along by contracting. In megacolon that muscle has stretched and lost its ability to contract effectively.
Faeces sit longer, water is absorbed out of them, they become harder, they are harder to move, and the colon stretches further. It is a one-way loop.
No laxative restores contractile function. That is why medical management works for a while and then stops working, and it is the key to understanding why surgery becomes the right answer rather than a last resort.
Common causes: idiopathic in most cats, and a narrowed pelvic canal from an old pelvic fracture in a meaningful minority. That second one is worth ruling out before the colon is blamed, because it is separately correctable.
The two questions owners ask
Does it actually end the cycle?
Yes, for the great majority. Long-term outcomes after subtotal colectomy are among the most satisfying in feline soft-tissue surgery. Most cats never obstipate again, and owners consistently describe a cat that is more comfortable and more itself than it has been in a long time.
Will my cat have diarrhoea forever?
Almost certainly not. Stools are soft to liquid for the first weeks, sometimes for a few months, because the colon's water-absorbing capacity has been reduced. In the great majority of cats they firm up to a soft-formed consistency that owners manage without difficulty. Permanently watery diarrhoea is uncommon.
Whether the ileocolic junction is preserved influences this, and it is a reasonable thing to ask your surgeon about.
When surgery is right
Not for a cat having a bad month. The candidates are cats with irreversible megacolon — repeated obstipation episodes, poor response to lactulose, prokinetics and diet, and a colon that is dilated on radiographs.
Waiting through repeated episodes is not neutral. Each one is uncomfortable, each requires sedation for de-obstipation, and the colon continues to stretch.
What is involved
The abdomen is opened, most of the colon is removed, and the remaining ends are joined. It takes one to two hours.
The main risk is leakage at the join, which is uncommon but serious, typically showing in the first few days. Infection and the usual risks of abdominal surgery apply.
Cats are stabilised first — many arrive dehydrated with electrolyte derangements and need a day or two of fluids and de-obstipation before anaesthesia is safe.
Recovery
- Two to four nights in hospital
- Loose stools from the start — expected, not a complication
- A cone for 10 to 14 days
- Restricted activity for two to three weeks
- A recheck at 10 to 14 days for sutures
Call your vet for vomiting that restarts, refusal to eat, fever, lethargy, or a swollen or discharging incision.
Litter tray hygiene needs more attention for the first months, and a cat with long fur around the hindquarters benefits from a trim.
Who isn't a candidate
- Concurrent condition: Constipation that is still responding to laxatives, diet and periodic enemas — surgery is for irreversible megacolon, not for a cat having a bad month.
- Other: Untreated underlying cause — a healed pelvic fracture narrowing the canal, a mass, or a neurological problem — where addressing the cause is the real answer.
- Concurrent condition: Significant dehydration, electrolyte derangement or an unstable patient; obstipated cats are often very unwell and need days of stabilisation first.
Common questions
How much does megacolon surgery cost for a cat?
Roughly $3,000 to $6,500, covering stabilisation with fluids and de-obstipation beforehand, the surgery, and two to four nights in hospital. Cats that arrive severely unwell and need longer stabilisation, or that develop complications, cost more.
What is a subtotal colectomy in cats?
Surgical removal of most of the colon, with the remaining ends joined together. It is done for megacolon, where the colonic muscle has stretched and permanently lost the ability to contract and move faeces along. Removing the failed segment breaks the cycle that laxatives can no longer control.
Will my cat have diarrhea after a colectomy?
Stools are soft to liquid for the first weeks and sometimes a few months, because the colon's water-absorbing capacity is reduced. In the great majority of cats they firm up to a soft-formed consistency that owners live with easily. Permanently watery diarrhoea is uncommon.
What is the life expectancy of a cat after colectomy?
Normal, in most cases. This is one of the more satisfying feline soft-tissue operations — the majority of cats never obstipate again and return to a comfortable life. The prognosis is driven far more by any underlying condition than by the colectomy itself.
Can megacolon in cats be treated without surgery?
Early on, yes — lactulose, prokinetic medication, high-fibre or low-residue diets, increased water intake and periodic enemas control many cats for a long period. But once the colonic muscle has permanently lost its ability to contract, no medication restores it, which is why medical management eventually stops working and surgery becomes the definitive answer.
Sources
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