Usefulness of Bisacodyl Testing on Therapeutic Outcomes in Refractory Constipation
Authors: Gabrio Bassotti
Maria Pina Dore
Edda Battaglia
Mario Grassini
Journal: Digestive diseases and sciences (2018)
Discipline: CLINICAL MEDICINE
Keywords: Bisacodyl test; Colonic manometry; Refractory constipation; Therapeutic outcomes.
Affiliations: Gastroenterology and Endoscopy Unit, Cardinal Massaja Hospital, Asti, Italy., Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy., Gastroenterology and Hepatology Section, Department of Medicine, University of Perugia School of Medicine, Perugia, Italy. ., Clinica di Gastroenterologia, Ospedale Santa Maria della Misericordia, Piazzale Menghini 1, 06156, San Sisto, Perugia, Italy. .

Abstract:  Background: Although chronically constipated patients usually respond to medical treatment, there is a subgroup with scarce/no response, generally labeled as refractory or intractable. However, whether this lack of response is real or due to ancillary causes (suboptimal dosage, lack of compliance etc.) is unknown. Aims: To see whether a pharmacologic test (bisacodyl colonic intraluminal infusion during manometric assessment) may predict the therapeutic outcome. Methods: Data of patients undergoing 24/h colonic manometry for severe intractable constipation in whom the bisacodyl test (10 ml of drug dissolved into saline and injected through the more proximal recording port) had been carried out were retrieved and analysed, and correlations with the therapeutic outcome made. Results: Overall, charts from 38 patients (5 men) were available; of these, only 21% displayed naive high-amplitude propagated contractions (average, less than 2/24 h), mostly meal-induced, during the recordings. A bisacodyl response was present in 31.6% patients, with a mean number of events of 1.8 per patient. After bisacodyl testing, 47.3% patients underwent intensive medical treatment, 44.7% surgery (medical failures), and 8% transanal irrigation, a procedure employed to treat refractory patients. The presence of naive propulsive contractions significantly correlated with the response to bisacodyl infusion (p &lt; 0.0001), and with a favourable outcome to intensive medical treatment (p &lt; 0.0001). Conclusions: The bisacodyl test may be clinically useful to better categorize constipated patients erroneously labelled as intractable and to exclude true colonic inertia, thus avoiding surgery in more than 30% of these subjects. 

Retracted: No

PubPeer comments:
 Could the authors explain whether an informed consent was obtained from the patient to perform a 24 h colonic manometric recording ? Also:  Intestinal transit time, measured by means of radiopaque markers, was delayed in all patients (from 120 to up to more than 240 h). Four patients had evidence of associated obstructed defecation, as documented by anorectal manometry and or defecography, and were unresponsive to biofeedback treatment. **Why patients with obstructed defecation were submitted to a 24 colon manometry? What was the benefit for these patients from this procedure, having the diagnosis already reached?** Is this approach consistent with current guideline? **Ethical Considerations Since this was a retrospective study, no individual patient identification was involved and no study-driven clinical intervention was performed; therefore, our IRB waived formal review and approval, deeming the study to be an extension of existing procedures.** This statement is obscure. Apparently the 24-hr manometry was not approved formally by the IRB? Can the authors explain.? ,