Rejection of a transplanted bowel

Rejection is when your body’s immune system starts to ‘attack’ your transplanted bowel. It happens when your immune system recognises the bowel as coming from a different person and thinks it isn’t supposed to be there.

Rejection can still occur even if you’re taking all of your medicines. If you don’t take your medicines as prescribed, the risks of rejection are higher. It’s very important to take all of your tablets exactly as they are prescribed for you.

Rejection happens in up to 30 to 40 in 100 patients within the first year of transplantation.

The risk of rejection is highest in the first 6 months after a transplant. After this time, your body’s immune system is less likely to recognise the bowel as coming from another person.

Chronic rejection happens in between 2 to 10 in 100 patients. It can be seen after an episode of severe acute rejection

Chronic rejection occurs after 6 months. Chronic rejection is when your body’s immune system continues to attack the donated bowel. Even if you take your anti-rejection medications, rejection can still occur. This is why it’s important to keep your appointments in clinic, and take the tablets that have been prescribed for you.

It may be possible to treat chronic rejection if identified early. But if untreated it may lead to death.

Rejection is suspected when the bowel starts to work less well. This is usually first picked up as diarrhoea (or higher output from a stoma), fevers, or poor absorption of nutrients. Sometimes rejection can be picked up before there are any symptoms at all by doing regular biopsies of the bowel.

Diagnosis almost always requires a bowel biopsy, where a sample of the bowel tissue is removed with an endoscope (telescope test) to look at under a microscope.

There are risks of bleeding and damage to the transplant, but these are rare. Your transplant team will explain the risks of having a biopsy to you.

Your health and your transplanted bowel will be closely monitored in clinic.

Treatment is with stronger immunosuppressant medicines, usually with intravenous steroids for 3 to 5 days. If these don’t work, or if you have severe rejection, then even stronger medications might be needed.

If the transplant rejection is picked up early, it can usually be treated successfully. It is possible for rejection to cause an organ to fail completely, but this is unusual. Sometimes surgery might be needed to remove bowel that has severe rejection in it that can’t be treated successfully.

The exact treatment will depend on the type of rejection you have.

There are different types of rejection, depending on which parts of the immune system are attacking the organ. Different types of rejection need different treatments.

The risk of rejection is most common in the first 6 months after bowel transplant (early rejection). Beyond this, as long as patients remember to take their prescribed immune suppression, at the correct dosage, late rejection is less common.

Almost all patients who experience acute rejection will need higher-dose steroids (usually intravenously for three days) as treatment. Some patients with acute rejection will need more than one course of steroid injections or require more powerful anti-rejection treatment. On occasion, antibodies specific to the donor organ can develop and this type of rejection may need anti-thymocyte globulin (ATG) treatment.

In the most severe form of rejection, the lining of the bowel transplant is lost. This causes a very high stoma output and also risks infection. It can take weeks or months for this to recover.

Rejection occasionally causes the bowel transplant to stop working completely.

Make sure you attend all of your appointments in clinic, and take the medications that have been prescribed for you. If you have side-effects from your anti-rejection medicines, tell your transplant team so that they can talk to you about other options. If you have diarrhoea or increased stoma output, or fevers, please let your transplant team know immediately.

Do not stop taking your immunosuppressant (anti-rejection) medicines.