Antroduodenal manometry

The digestive system is a hollow tube from the mouth to the anus (where poo leaves the bottom). The walls of the tube contain muscles and nerves that squeeze food rhythmically through the system. If the muscles and/or nerves are not working properly, food cannot pass through the digestive system.

Manometry is a way of measuring how well the muscles and nerves in the digestive system are working. Antroduodenal manometry looks specifically at the muscles and nerves in the stomach and small intestine.

You will already have received information about how to prepare your child for the manometry in the admission letter.

The person bringing your child to the test should have ‘parental responsibility’ for them. This is someone who has legal rights, responsibilities, duties, power and authority to make decisions for a child. If the person bringing your child does not have parental responsibility, we may have to cancel the test.

The doctor will explain about the test in more detail and discuss any worries you may have. They will ask you to sign a consent form giving permission for your child to have the test.

If your child has any medical problems, particularly allergies, please tell the doctor about these. Please also bring in any medicines your child is currently taking and show these to the doctor.

If your child is taking any of the following medicines these will need to be stopped at least 48 hours before the test starts: erythromycin, domperidone, azithromycin, nifedipine, cyclizine, buscopan or opiates such as morphine.

The test can still be carried out if your child currently feeds using a gastrostomy or gastrojejnostomy (transgastric jejunal feeding device) but please bring a spare device of the same size with you.

Your child will need to come to hospital the day before the test. The nurse or doctor will put a thin tube (cannula) into a vein in their arm.

We will apply some local anaesthetic cream before we do this, so that the skin is numb. Your child may like to have a cold numbing spray before the needle instead of the cream.

We will also take a blood sample from the cannula to check your child’s salt and mineral levels.

Your child must not eat anything from midnight the night before the test. If your child has parenteral nutrition or overnight feeds, this will also be stopped at midnight. We’ll give your child intravenous fluids (fluids via a vein) from midnight to make sure they stay hydrated.

Your child can drink water until 6.30am on the day of the test. After this they should not drink anything.

Your child will first be placed under a general anaesthetic which will make them ‘sleep’. Once they’re asleep the doctor will insert a catheter (a flexible plastic tube). This catheter contains lots of sensors that can record nerve and muscle reactions.

The catheter will go up one of your child’s nostrils and down the back of their throat until it reaches their stomach. The doctor will use x-rays and guide wires to move the catheter from the stomach into the small intestine.

The catheter will be taped to keep it in place. The end of the catheter outside the body will be attached to a machine during the test, to measure how well the muscles and nerves are working.

If your child has a gastrostomy or gastrojejunostomy device, the catheter may be passed through the gastrostomy site. A smaller naso-gastric tube may be passed into their nose or alongside the manometry catheter.

Once your child has woken up you will be able to join them in the recovery room. You will be able to stay with them for the rest of the test.

The tube should not hurt but may be uncomfortable as is quite thick and it is taped to the nose or onto the stomach. Your child will be restricted with the movements they can make.

Your child will be ready to start the manometry when they’ve fully recovered from the anaesthetic.

The test will be carried out by your child’s bed on the ward.

Your child will need to have regular blood tests during the test to check the sugar and salt levels in their blood. A nurse will be caring for your child throughout the test. A doctor will assess what happens when your child is fasting and has food.

Your child won’t be able to have food for most of the test. They will be given intravenous fluid to keep them well hydrated. They can also drink water (only) if they would like. Towards the end of the test they will need to have something to eat and drink.

If your child does not usually feed by mouth or into their stomach, a member of the Motility team will discuss this part of the test with you.

The test will last for approximately 48 hours.

Your child may have a nosebleed when the catheter is inserted into their nose. This is because the guide wires can cause a small scratch.

There is a very small risk that the catheter could cause damage to the digestive system when it’s inserted. As the catheter is flexible and the doctors and nurses are very experienced this is very unlikely.

There is a very small chance that the salt levels in your child’s blood may be affected. We will closely monitor this throughout the test. If your child’s salt levels fall below the normal ranges, we will change the intravenous fluids to correct this.

Once the test is complete, the nurse will remove the catheter.

If the catheter was placed via a gastrostomy site, a new gastrostomy button will be placed as soon as the manometry catheter is removed.

If your child has a gastrojejunostomy, the manometry catheter will be left in place. A new device will be inserted by the Interventional Radiology team, using the manometry catheter to help them.

Provided no other tests are planned, the nurse will remove the cannula before you leave the ward.

Unless you have been advised otherwise, your child can start eating and drinking and restart any medications that were stopped for the test.

Most children usually recover quickly from a general anaesthetic. Some children may get side effects, but these are usually mild. Common side effects include:

• headaches
• feeling sick or being sick (vomiting)
• a sore throat

These can usually be treated effectively with medicines.

Other side effects include:

• tiredness
• dizziness
• disturbed sleep patterns for a few days

These effects generally just need time to wear off.

You should call 111 if your child:

• becomes generally unwell
• refuses to eat or drink
• is sick (vomits)
• is unusually sleepy or it is difficult to wake them up.

If you have any questions, please call the Gastroenterology Investigation suite on 020 7405 9200 ext 0212 (Tuesday to Friday, 8am to 6pm).

Out of hours call 111. In an emergency call 999 or go straight to your nearest Accident and Emergency (A&E) department.

We will discuss the results at your child’s next outpatient appointment. The analysis of this test is complicated so it can take some time to get the results. If we need to start your child on a new treatment before the appointment, we will contact both you and your child’s GP.

If you have any questions, please call the Gastroenterology Investigation suite on 020 7405 9200 ext 0212 (Tuesday to Friday, 8am to 6pm).