What is intestinal failure? An expert gastroenterologist explains
Written in association with:Intestinal failure is becoming slightly more common but still remains the rarest type of ‘organ failure’. Therefore, patients with IF are often referred to one of a few specialist hospitals in the UK. University College London Hospital, where consultant gastroenterologist Dr Shameer Mehta practices, is one such specialist hospital. He makes up part of a large team of specialist nurses, dieticians, pharmacists and doctors which provides multi-disciplinary care to patients with IF. He offers us an overview of this rare condition.
What is intestinal failure?
Intestinal failure (IF) is a condition in which the gut loses its ability to digest and absorb nutrients and water to such an extent that artificial feeding, also known as ‘parenteral nutrition’ or ‘PN’ is required.
What are the main causes?
There are a variety of reasons patients develop IF, such as after bowel surgery due to a condition called ileus - which is the most common type of IF and rarely leads to long-term complications. After operation, the bowels take some time to start working, meaning patients are unable to eat and drink normally. If this lasts for more than a few days, then PN is required to avoid malnutrition.
Long term IF can also occur after the removal of long segments of bowel, typically the small bowel, which is responsible for the majority of absorption of nutrients and calories.
One of the most common conditions for which patients have bowel surgery is Crohn’s disease. When there is not enough bowel left after an operation, patients can lose excessive amounts of nutrients, fluid and salts through their stool. Eating more can actually make this worse, meaning that PN is required.
In addition, some patients may develop blockages of the bowel for a variety of reasons, including Crohn’s disease or certain cancers. This severely limits their appetite and ability to eat and drink normally, meaning PN is required.
What are the symptoms of intestinal failure?
Intestinal failure itself is not responsible for symptoms per se. However, patients can unfortunately develop multiple unpleasant symptoms from the underlying causes of IF. These include:
- a lack of appetite
- nausea
- vomiting
- diarrhoea
- abdominal pain
The type of symptoms will depend on the underlying cause. For example, patients with blockages of the bowel will often have nausea and/or vomiting together with a lack of appetite.
Who is most likely to have the condition?
The underlying causes of IF can occur in patients of any age, meaning that IF can also occur at any age.
Patients with Crohn’s disease who were diagnosed at an early age or who have had previous operations in which sections of bowel have been removed are at particular risk of developing IF. Similarly some patients with cancer that has spread to the abdomen may also develop IF. However, IF is rare and most patients with these conditions do not develop IF.
Some patients suffer with conditions which require the formation of a stoma bag. This is where a section of bowel is brought to the surface of the skin. Most stomas work well, but some patients may develop a ‘high output stoma’, often due to a condition called short bowel syndrome. This describes a situation in which the amount of stool being emptied into a stoma bag is higher than normal, which means the gut isn’t absorbing enough water, salts and nutrients. Unfortunately, drinking more fluids may actually make this worse. Usually, the only solution is to provide PN.
What are the tests used to diagnose intestinal failure?
The development of IF in a patient is usually obvious to a medical team, but the diagnosis relies on a combination of factors and tests. These include:
- Dietary history – a specialist must understand what and how much a patient is able to eat and drink on a daily basis. Some patients are not able to eat and drink enough regularly, perhaps because of an underlying gut problem.
- Nutritional and hydration tests - these include testing for specific features which may be present on examination such as weight loss, a dry mouth or if there are any changes in blood pressure.
- Specific body measurements – these include skinfold thickness or handgrip strength, which can be helpful when compared over time.
- Blood tests – they are often performed to check for malabsorption and the consequences of malnutrition and dehydration.
- Urine tests – examining salt levels in the urine is also important and may detect dehydration sooner than by relying on blood tests alone.
- Measurement of faeces - the measurement of the amount of faeces collecting in a stoma bag every day (if a patient has a stoma) is helpful, since an amount greater than approximately 1200-1500ml per day is considered abnormal.
How is intestinal failure treated?
By definition, patients with IF require artificial feeding into the bloodstream. This may be a short-term measure, until an acute problem has resolved (e.g. recovery after an operation) or a longer-term measure if the underlying cause cannot be resolved quickly.
Feeds are delivered into the veins through ‘catheters’ or ‘lines’ which are specially designed for long-term use. These lines are safe to use outside of the hospital setting although need to be well cared for to avoid infections.
In the majority of patients, feeds are delivered overnight whilst patients are asleep meaning that they can go about their usual activities during the day. This can be done safely within patients’ own homes, although it sometimes requires supervision by specialist hospital teams working closely with specific contractors (homecare companies) who are responsible for delivering feeds wherever necessary.
In addition to PN or intravenous fluids, certain medications or lifestyle changes can also help. These include:
- Omeprazole - this drug, among others, reduces the amount of gut secretions
- Loperamide or codeine – this slows down the bowel to improve absorption
- Growth factors – newer drugs, such as tedulglutide, have been shown to improve bowel function and reduce the need for PN. However, this drug is not available in all countries and trials are ongoing to find out whether other similar drugs are also effective.
- Dietary changes - this can also improve bowel function and reduce the need for PN, including modifying fibre intake and increasing the intake of calorie-dense foods.
Clearly, treatment of the condition causing IF in the first place will also help to treat IF itself. For example, treating Crohn’s disease will improve absorption in the gut meaning the need for PN can be reduced.
In many patients the remaining bowel can adapt over time and start to absorb more. Consequently, the amount of PN required can decrease during this period.
PN at home is usually safe, but no matter how many precautions are taken, some patients can develop complications of long term PN or IF itself. If these complications become very frequent or life threatening then a small bowel transplant can be considered.
Bowel transplant operations are not common but outcomes after bowel transplant are improving. Generally, patients do better on PN at home than having a bowel transplant which is why home PN is the preferred treatment.
Dr Shameer Mehta is an expert consultant gastroenterologist based in London, specialising in pelvic radiation disease, inflammatory bowel disease and nutritional disorders, among others. To book an appointment with him visit his profile here and book online.
