EP677 - The Effect of Melatonin in Patients with Low Anterior Resection Syndrome – A Randomized, Placebo-Controlled, Cross-Over Trial

Monday, May 12, 2025

8:43 AM – 8:48 AM PT

Location: Monitor 10, Sails Pavilion, Upper Level

ePoster Presenter(s)

Jawad A. Zahid, MD (he/him/his)

MD & Ph.D.-student
Center For Surgical Science
Køge, Sjelland, Denmark

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

MM

Michael T. Madsen, Ph.D.

Research Coordinator, part-time lecturer, Surgical resident
Slagelse Sygehus
Slagelse, Sjelland, Denmark

Disclosure information not submitted.
BC

Britt Cappelen, n/a

Bioanalytiker/lab manager
sjællands universitets hospital CSS
Køge, Sjelland, Denmark

Disclosure information not submitted.
FM

Frederikke Agerbo Modin, BSc

Statistician
Omicron ApS
Oesterbro, Sjelland, Denmark

Disclosure information not submitted.
OB

Orhan Bulut, n/a

Associate professor of Surgery
Copenhagen University Hospital Hvidovre
Copenhagen, Hovedstaden, Denmark

Disclosure information not submitted.
PC

Peter Christensen, DMSci

Professor
Department of Surgery, Aarhus University Hospital
Aarhus, Midtjylland, Denmark

Disclosure information not submitted.

Senior Author(s)

IG

Ismail Gögenur, DMSci

Consultant
Zealand University Hospital
koege, Sjelland, Denmark

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

All of the relevant financial relationships listed below have been mitigated.

Jawad A. Zahid, MD: This individual has no financial relationships with ineligible companies.

Ismail Gögenur, DMSci: This individual has no financial relationships with ineligible companies.

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Purpose/Background: The majority of patients who undergo rectal cancer surgery avoid a permanent stoma but suffer from low anterior resection syndrome (LARS). Evidence-based treatment options for LARS are lacking. Previous studies have shown that melatonin affects bowel motility and has anti-inflammatory effects in the intestinal canal, but it has not been tested in patients with LARS. The objective of this study was to investigate whether treatment with melatonin had an alleviating effect on LARS symptoms and, secondarily, its effect on bowel movements, quality of life, mental health, and sleep.

Methods/Interventions: This was a multicenter, randomized, placebo-controlled, quadruple-blinded, crossover trial investigating the effect of 25 mg melatonin versus placebo administered rectally by the patients as an enema every night before bedtime. Patients with major LARS between 3 to 24 months after surgery were randomized to either four weeks of melatonin or placebo, followed by a four-week washout period, and then four weeks of the opposite treatment. The primary outcome was the change in the LARS score between treatments. Secondary outcomes were bowel movements, quality of life, mental health, and sleep.

Results/Outcomes: Of 18 randomized patients, 13 were included in the analyses. Patients experienced a change in LARS score of -2.08 (SD: 4.41) after melatonin treatment and -2.54 (SD: 6.75) after placebo. The mean difference between treatments was -0.46 (CI -5.52 to 4.60), p=0.85. There was no clinically relevant difference in daily bowel movements, quality of life, depression, anxiety, or sleep between the melatonin and placebo treatments.

Conclusion/Discussion: In our study, melatonin did not have an alleviating effect on LARS symptoms but was safe to use as a self-administered rectal enema. Furthermore, we could not observe any clinically relevant effect of melatonin on bowel movements, quality of life, mental health, or sleep. Continued high-quality research is needed to investigate both established treatment modalities and novel and innovative approaches to tackle LARS.