Interferential therapy (IFT) for the treatment of constipation and soiling in children

What is interferential therapy (IFT)?

Interferential therapy (also referred to as transcutaneous electrical stimulation or TES) is a non-invasive treatment. It involves the application of a low frequency electrical current, through the abdominal wall, to modulate (attune) the nerves of the large bowel. You may have heard of TENS machines (used for pain management and often used by women in labour) which use very similar low frequency electrical currents.

During IFT for children with constipation and/or soiling, electrode pads are placed on the abdomen and the back of your child. The pads are then connected to the IFT machine with wires. Your child needs to keep the pads on for one hour per day throughout their treatment programme. Children will be able to feel a slight pulsing on their skin but nothing more. After one hour the pads are removed and kept for the next treatment session on the following day.

Why has IFT been suggested for my child?

IFT has been shown to:

• decrease soiling
• increase frequency of passing stool
• increase the sensation of needing to pass stool
• improve the time it takes for stool to pass around the large bowel

No harmful events have been seen with the use of IFT.

Research findings help us to identify children who are most likely to have their constipation and soiling symptoms improved by the use of IFT.

IFT has been suggested for your child because your child:

• is aged over four years
• has a long history of constipation which has not resolved with the use of medicines
• has undergone a transit x-ray study and the results indicate that they have a type of constipation which IFT can improve
• has had a normal rectal biopsy

Where does IFT take place and how often?

IFT is undertaken at home. You will be supplied with the required equipment and taught how to use it.

IFT needs to take place for one hour every day for a period of three to six months. You should aim to use IFT at approximately the same time each day.

Who will teach us how to use the IFT equipment?

You will be taught how to use the IFT equipment in the outpatient clinic by a member of the paediatric surgery team that specialises in the care of children with complex constipation problems. Teaching will include:

• demonstration on the use of the equipment
• proper placement of electrodes
• appropriate connections of leads
• reassurance on the safety of IFT for home treatment
• regimen to be followed
• how to complete the bowel diary
• how to complete the symptom severity score questionnaire

What else do we need to do?

It is essential that you keep a detailed bowel diary (the diary will be provided for you) to help us to adjust your child’s treatment plan. The bowel diary must be maintained throughout treatment and needs to include:

Before taking an IFT machine home, you will be asked to provide written agreement that the machine will be cared for appropriately and returned at the end of the child’s treatment, or earlier if the child discontinues treatment.

What are the risks of IFT?

Children who have a pacemaker or children who have a shunt to help fluid drain around their brain (called a VP shunt) cannot receive IFT therapy. If IFT has been suggested for your child and they have a pacemaker or shunt you must inform their consultant or nurse specialist.

For all other children, IFT does not have any associated risks. Occasionally, children may have a skin reaction to the sticky pads used. If redness is seen when the pads are removed, please inform your child’s nurse specialist.

What are the alternatives to IFT?

IFT is offered to appropriate children as an additional step on their management pathway to help with constipation and soiling.

Alternatives are to:

• continue to try and manage constipation with medication
• take the next step on the management pathway which, for most children, involves the use of trans-anal irrigation (TAI). TAI involves the use of specialist equipment to help wash stool (poo) out of the lower end of the bowel by passing a small tube into the anus (bottom hole). We have a leaflet about TAI in children; please ask if you would like a copy.

Setting up and using the IFT machine

The interferential stimulator used at Addenbrooke’s is the NeuroTrac IFC Rehab (IFC184) machine manufactured by Verity Medical Ltd.

Placement of electrode pads

Two self adhesive 4 x 4cm electrodes are placed on the front of the abdominal wall at the level of the umbilicus (belly button) of the child. Two further electrodes are placed on the child’s back between specific bones in the spine (called T9 and L2) on either side (see diagram below).

Connect lead cables to electrodes. The lead pins must be fully inserted into the electrode connector as shown below.

• Place electrodes onto the child’s abdomen and back as shown in the diagram above. Press the electrodes down firmly to ensure a good seal onto the skin.
• Insert the plugs at the end of the electrode lead cables into the IFC machine’s device output sockets marked IFC CH.1 and CH.2 as shown below (either lead can be inserted into either CH.1 or CH.2 socket).

• Press the on/off button to switch the machine on. The machine will start up with the previously selected programme.

• Check the programme is correct: The display should read 'PC1' in the top right-hand corner of the IFC display screen (see below). If it does not read 'PC1' then press the IFC button labelled ‘PROG’ until the display reads 'PC1'.

• Check that the Hertz is set at 150. The display should read '150Hz' in the top left-hand corner of the IFC display screen. If it does not, press and hold the IFC button labelled ‘SET/ESC’ for three seconds. Once the Hz sign is flashing on the display, use the '+' and '–' buttons to adjust accordingly. Once the reading says '150Hz', press the button labelled ‘SET/ESC’ again to save this setting and return to the home screen.

• Set the intensity (in milliamps, mA) using the IFC buttons labelled ‘+’ and ‘-‘. Ensure you adjust intensity on leads 1 and 2 equally. The intensity will be different for each child but should be set at a level which feels comfortable. A gentle pulsation on the skin should be felt.

• IFT has begun. The machine will start its count down of 60 minutes automatically. During IFT your child should sit still but could undertake homework, watch TV or read during this time to occupy them.

• After 60 minutes of therapy, use the on/off button to turn the machine off. Carefully remove the electrode pads and stick these back onto the plastic protective sheet ensuring you stick them to the correct side as marked.

What reviews will take place during IFT?

Your child will require regular reviews to discuss progress and adjust their treatment plan:

• Approximately two weeks after IFT commences you will receive a telephone clinic appointment with the nurse specialist.
• After a further eight weeks you will receive another telephone clinic appointment with the nurse specialist.
• Your child will then need to be reviewed in a face-to-face clinic with the consultant and nurse specialist approximately three months after commencing IFT treatment. Your child’s symptom severity score will also be reassessed via a questionnaire.

You must have your completed bowel diary available for each of the above reviews.

Will IFT definitely improve my child’s symptoms?

We cannot guarantee that IFT will improve symptoms in every child that has the therapy. To help ensure improvement in symptoms, it is essential that your child is committed to undertaking a programme of therapy at home and it is essential that you are committed to supporting your child. When IFT fails to improve symptoms the main reason is that the child and their family members/ carers are not committed to use and support of the programme of therapy.

Return of the IFT machine

The interferential machine remains the property of Addenbrooke’s Hospital and as such must be returned by you at the end of the treatment programme or earlier if the programme is discontinued.

Chaperoning

During your child’s hospital visits they will need to be examined to help diagnose and to plan care. Examination may take place before, during and after treatment, is performed by trained members of staff and will always be explained to you beforehand. A chaperone is a separate member of staff who is present during the examination. The role of the chaperone is to provide practical assistance with the examination and to provide support to the child, family member/ carer and to the person examining.

For further information/ queries please contact your nurse specialist on 01223 586973, Monday to Friday, 08:00 (8am) to 18:00 (6pm).