Anal irrigation: how does transanal bowel irrigation work?

Key facts at a glance

• In transanal irrigation, water is introduced via a rectal catheter, triggering the emptying reflex
• It is an option when conservative bowel management over at least six weeks is not sufficient
• There are absolute contraindications – suitability must be checked by a doctor beforehand
• Repeated professional instruction is a prerequisite, not an extra
• Bowel perforations are very rare, but documented

For people with neurogenic bowel dysfunction – for example after a spinal cord injury – bowel emptying can take hours and dictate the daily routine. Transanal irrigation is one of the procedures that can change this. This article explains how it works, who it is suitable for and where its limits lie.

How the procedure works

The professional society's guideline describes it like this: via a rectal catheter – with balloon or cone – an individually determined amount of water is introduced. This triggers the emptying reflex and the recto-anal inhibitory reflex.

There are three ways of introducing the water: by gravity, by a manual or by an electric pump system. Which system fits depends on hand function, the seating situation and the amount of water required.

What comes first

Irrigation is not the first step. The guideline names as a prerequisite that conservative bowel management has been tried and documented over at least six weeks. This includes:

• stool modulation through diet and fibre – psyllium husks, linseed
• adjusted fluid intake
• if necessary, laxatives tolerated in the long term
• digital evacuation or stimulation, suppositories, enemas

As a basis, the guideline recommends regular meals, 1500 to 2000 ml of fluid daily and up to 30 g of fibre – with the full amount of fibre, two litres of energy-free fluid are advisable. This recommendation carries 100 percent consensus.

The contraindications

This part is the most important. The guideline provides a checklist that is worked through before the first application.

Absolute contraindications

• acute infections in the abdomen – appendicitis, diverticulitis, acute gallbladder inflammation, acute flare of a chronic inflammatory bowel disease
• narrowing processes in the rectosigmoid and untreated bowel cancer
• surgery on the rectosigmoid less than three months ago
• up to four weeks after removal of polyps from the rectum or colon
• ischaemic colitis
• unexplained anal bleeding or unexplained pain
• unexplained changes in bowel habits

Relative contraindications

Here a careful assessment is needed, not an exclusion:

• diverticulosis, faecal impaction
• anal conditions that can cause pain or bleeding – anal fissure, anal fistula, symptomatic haemorrhoids
• long-term steroid therapy, immunosuppression
• existing pregnancy
• bleeding tendency or treatment with anticoagulants
• autonomic dysreflexia or unstable circulation
• children under three years
• a history of major pelvic surgery or radiotherapy of the abdomen and pelvis

Before starting, the guideline provides for a proctological examination to clarify the reflex situation and spasticity of the anal canal. In the case of warning signs – bleeding, mucus discharge or changed bowel habits – a colonoscopy should be arranged.

How high is the risk of perforation?

A bowel perforation is the most serious conceivable complication. It is very rare, but real. In a safety evaluation, two non-fatal bowel perforations were found in around 110,000 irrigation procedures.

This figure is the reason why the contraindications and professional instruction are not a formality. It is at the same time the reason why the procedure is considered acceptably safe.

Another point is remarkable: in known autonomic dysreflexia – a dangerous blood pressure crisis that can be triggered by bowel distension – the symptoms with transanal irrigation occur, according to the guideline, less often and more mildly than with digital evacuation.

The rhythm in everyday life

The goal is emptying at the same time of day every time. The guideline names as guide values:

• with a lesion above the sacral cord: every one to two days
• with a lesion of the lower motor neuron: once or twice a day
• emptying time per session: under one hour

Before bowel emptying it makes sense to empty the bladder.

Instruction is a prerequisite

The guideline puts this unusually clearly:

“Competent and repeated instruction in handling as well as adequate troubleshooting are prerequisites for successful use.”

Repeated, not once. The first weeks are an adjustment phase: the amount of water, timing and rhythm are adjusted until the result is reliable. Anyone who gives up after two attempts has not really tried the procedure.

Frequently asked questions

Balloon or cone catheter?

Both are named in the guideline as variants. The balloon seals and holds the water back, the cone is held in place during the inflow. Which system is suitable depends on sphincter tone and hand function and should be assessed professionally.

How long does an application take?

The guideline sets a target emptying time of under one hour per session. In the adjustment phase it can take longer.

Does the health insurance fund cover the costs?

Irrigation systems are medical aids and can therefore in principle be prescribed. How the supply process works is explained in our article on medical aids on prescription.

How up to date is the guideline?

The underlying S2k guideline was valid until 07/2024; a review was scheduled for 08/2024. The AWMF currently lists it as expired and notes on the document that it is being revised. The contents given here reflect its last published version – please always clarify use with your doctor.

Your next step

We stock irrigation systems and accessories from Coloplast and Qufora – balloon and cone catheter systems, replacement catheters and accessories. With a prescription, we handle the coordination with your health insurance fund.

Sources

• S2k guideline “Neurogenic bowel dysfunction in spinal cord injury”, AWMF register number 179-004, valid until 07/2024 (in German)
• Long-term outcome and safety of transanal irrigation for constipation and fecal incontinence, PubMed