Colostomy is a surgical procedure used in cats to promote healing of rectocutaneous fistulas that form as a result of type II atresia ani. Rectocutaneous fistulas are small tunnels that form from the rectum through the skin leading to leaking of rectal contents through the skin. These fistulas are thought to form due to the inflammation associated with type II atresia ani. Atresia ani is an extremely rare congenital condition in cats in which the rectum and anus does not form properly. The rectum may not communicate to the anus or the anus may be absent.  The goal of colostomy is to divert fecal material to bypass the fistulas and promote healing and fistula closure. The colostomy is then reversed and normal function established. Your veterinarian will refer this to a boarded veterinary surgeon for correction. 

Before surgery, the veterinarian will give your cat a thorough physical exam and ensure that your cat is healthy enough for surgery with basic bloodwork. It will be important to assess your cat closely for other congenital conditions that may need correction or indicate that euthanasia is the best course. As with most surgery, you cat will need to be kept off food for 24 hours the day before surgery to ensure that there is not an adverse reaction to the anesthetic medications used. The steps of the surgical procedure are detailed below. 

Though a rare procedure, those cases of rectocutaneous fistulas in cats caused by atresia ani that have been treated using colostomy have been successful. Cats typically regain continence after the colostomy is reversed and the rectocutaneous fistulas, once healed, do not recur after the atresia ani is corrected.

Your cat will likely be placed on pain medication and antibiotics for the first few days after surgery to reduce pain and swelling associated with surgery and prevent infection associated with a “dirty” surgery. In addition to pain medication and antibiotics, your cat will be prescribed medicine to promote colonic motility and stool softeners to prevent constipation. Your cat will also need to wear an Elizabethan collar to prevent licking or traumatizing the surgery site. After surgery, your cat should have normal bowel function, however, due to the colostomy they will be incontinent. Follow-up with your veterinarian will be scheduled to ensure that the fistulas are healing and to schedule a reversal procedure. 

The cost of colostomy is high due to the specialized nature of the procedure and the fact that there are two surgeries associated with this procedure. Cost can range from $1,500 to $2,500. 

This is a very rare procedure associated with a rare condition. Not every veterinary surgeon may be able to perform this procedure, so your cat may need to be taken to an academic veterinary hospital for treatment. The few reported cases in the literature have had favorable outcomes with cats retaining continence once the colostomy is reversed.

Preventing the need for colostomy involves recognizing kittens with atresia ani early since the rectocutaneous fistulas associated with this condition are thought to be formed due to prolonged inflammation from untreated atresia ani. Preventing atresia ani involves preventing breeding cats with a known history of atresia ani.