Transanal irrigation (TAI)—also known as rectal irrigation—is an accepted treatment for neurogenic bowel dysfunction (NBD). It’s also emerging as a therapy for chronic idiopathic constipation (CIC), yet very little research has been done to determine its efficacy in patients with this condition.
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TAI “typically involves transanal insertion of a rectal catheter or cone in order to instill lukewarm water retrograde into the colon. This is achieved through various commercially available irrigation systems which have either hand controlled or mechanical pumps, in a volume ranging from 500 mL to 1,000 mL depending on patients’ experience and tolerance. This is then drained naturally after a few minutes and can result in a satisfactory bowel movement,” wrote researchers in a recent paper that studied the treatment’s efficacy in patients with refractory CIC.
In this interview, study author and colorectal surgeon Dr. Kevin J. Etherson, of Durham University, in Durham, United Kingdom, discusses the promising results of this study and how this minimally-invasive treatment may benefit patients with CIC when medical and behavioral therapies have failed.
MDLinx: What led you to undertake this study?
Dr. Etherson: I undertook this study of TAI for CIC as an additional project when I was working as a researcher for Professor Yan Yiannakou, MBChB, MRCP, MD, also of Durham University. We had a tertiary referral clinic for CIC patients who had failed all current/novel medical treatments and biofeedback therapy, and who were trying TAI as a possible bridging therapy before considering sacral nerve stimulation or surgery. We had the largest cohort of these patients in the North of England and so this study seemed sensible, although it is limited scientifically.
MDLinx: Your study found that 67% of patients reported they were either moderately satisfied or very satisfied with the treatment. Did this finding surprise you?
Dr. Etherson: This did not surprise me or the professor. Our experience from the clinic meant we expected this result. This suggests to me that the patients found this a very easy therapy to perform at home, and that it was clearly having some sort of effect where medications had failed, as these patients were at the severe end of the spectrum.
MDLinx: More than 42% of patients reported improvement in 4 out of 6 major symptoms. If that’s true, why aren’t more patients with CIC using this therapy?
Dr. Etherson: Very few high-quality research papers have been published so far on TAI as a therapy for CIC, and so most clinicians (outside of research clinicians) would be very skeptical about prescribing it. It’s also an expensive therapy costing anywhere between £700 to £1600 per year in the UK (about $900 to $2,000) depending on the equipment used.
MDLinx: More than 20% of patients reported an adverse event. Does this count against the usefulness of TAI as a therapy?
Dr. Etherson: The adverse events were all relatively minor. More than half were due to equipment malfunctions such as catheters splitting (3%) and balloons bursting (10%), which did not harm the patients involved.
Medical problems were also relatively minor with no serious complications. These included rectal bleeding (6%), painful irrigations (3%), painful hemorrhoids (2%), and new anal fissures (2%), but no perforations (0%)
I would, therefore, conclude that these are to be discussed with patients before starting the therapy but do not restrict the use of the therapy, especially as this therapy is used in patients with severe CIC symptoms after failure of conventional medical treatments.
MDLinx: In the paper, you point out that current treatment algorithms for CIC in both Europe and the US have failed to adequately recognize the value of TAI treatment. Why has this treatment not been well recognized?
Dr. Etherson: Again, TAI has still to undergo high-quality prospective trials of efficacy and safety, and this is the primary reason it has been overlooked in CIC treatment algorithms in both the EU and US. I expect in the next five years it will feature in both, once the evidence reaches a satisfactory scientific standard.
MDLinx: What is the next step in this line of research?
Dr. Etherson: Currently in the UK, there is a multicenter national trial of various therapies (such as TAI) for CIC being investigated by Professor Charles Knowles of Queen Mary University of London. This is a prospective, high-quality trial and will inform us greatly about these therapies that lie between medically refractory CIC and formal surgical treatments such as colectomy and antegrade colonic enema procedure.
About Dr. Etherson: Kevin J. Etherson, MBChB, MRCSEd, is a postgraduate researcher in the School of Medicine, Pharmacy and Health at Durham University, and a surgeon in the Department of Colorectal Surgery, County Durham and Darlington NHS Foundation Trust, in Durham, UK.