The intestine is connected to lymph vessels. These give the rest of the body lymph. This is a special protein fluid full of lymphocytes, which are white blood cells that help fight infection.
In PIL, the lymph vessels connected to the lining of the small intestine are very swollen. This causes lymph to leak into the intestine.
What causes primary intestinal lymphangiectasia and who can get it?
What causes PIL is not known. It can happen to people of all ages but it is quite rare.
What are the key warning signs?
The symptoms of PIL can include swelling of the legs, extreme tiredness and pain in your tummy area. Some people lose weight and get diarrhoea.
How is it normally diagnosed?
In most cases this is diagnosed in children, usually before a child is three years old. Most people are diagnosed because they have noticed a swelling in their leg.
If a doctor thinks a child may have PIL, they will have to examine the small intestine. This is done using a process called endoscopy. This is where a small camera is inserted into the intestine so the doctor can have a look around. The child will be asleep when this is done so won't feel a thing.
The doctor will take a small sample of the tissue from the intestine so it can be examined.
Other tests may include a blood test or a stool sample, where the child's poo will be looked at to check if everything is normal. Sometimes the doctor will also cary out a scan using a special x-ray machine to look at the intestine more closely.
How is it treated?
Most people with PIL are put on a low-fat diet but they also have to take special supplements to make sure they are getting the right vitamins and nutrients.
Usually after a few weeks of this treatment, the level of protein in the blood rises toward normal. This special diet must be continued for life to keep the symptoms under control.
In some rare situations, surgery might be considered. In some cases recently doctors have performed a small bowel transplant for people who did not respond to other treatments.
Can it be prevented?
As doctors do not know what causes PIL, there is no way it can be prevented.
When should you seek medical help?
A child should be taken to the doctor if parents notice any swelling in the legs. If a child has these symptoms parents should speak to your GP to see if he or she needs to arrange tests.
What about future health?
PIL can be kept under control if the child stick to a low-fat diet. They will probably be referred to a dietitian who can advise on what can and can't be eaten.
Last reviewed by Great Ormond Street Hospital: 7 January 2009