Colorectal surgery

About Colorectal Surgery Research

Our Colorectal Surgery Research is improving surgical outcomes for our patients by investigating issues like the connection between gender and the outcome of surgery for large bowel cancer, taking medical records online with eHealth and the prevention of perineal problems in first time mums electing for caesarean section.

Unit head

  • Mr William Teoh

Director of Research and Education

Supervisors: Mr William Teoh, Dr Thomas Suhardja
Location:   Dandenong Hospital
Tel: 9554 8657 Email:

Colorectal surgery research project

Title : Compound topical ointment vs placebo for posthaemorrhoidectomy analgesia – a prospective doubleblinded randomised controlled trial.

Description: Haemorrhoidectomy is a commonly performed surgical procedure. It is regarded as the first choice treatment for grade III and IV or recurrent haemorrhoids. Conventional haemorrhoidectomy is associated with post procedural pain in the immediate and intermediate setting. Pudendal nerve block is superior to simple perianal block in managing immediate postoperative pain i.e. within the first 24 hours. However, this index analgesia has considerable limitation in the intermediate setting. Other topical agents such as glyceryl trinitrate ointment and metronidazole have shown some evidence in alleviating pain in the intermediate setting, but are not always reliable. We propose a new regime of topical ointment to improve analgesia in the immediate and intermediate posthaemorrhoidectomy setting. The proposed compound topical ointment consists of gabapentin 6%/ketamine 5%/amitriptyline 2%. Theoretical benefit of the ointment would be immediate, with usage over frequent time intervals required to maintain analgesic effect. Various studies have shown promising outcome for the use of compound topical ketamine and amitriptyline on neuropathic pain. This study will be the first of its kind investigating its use on posthaemorrhoidectomy patients.  We aim to perform a prospective randomised controlled trial comparing conventional analgesia to this new regime of compound topical ointment. The study will be prospective, doubleblinded, with patients randomised to either receiving the compound ointment or placebo ointment. There will be a total of 75 patients on each arm. Both arms will be receiving formal haemorrhoidectomy with the conventional intraoperative pudendal nerve block, and postoperative oral opioid pro re nata. Ointments will be prepackaged and unlabelled by pharmacy, in order to keep the patients, treating team and data analyst blinded. Unlabelled ointments will be provided to patients from postoperative day 1 onwards. Assessment of pain will be performed using a simple Visual Analogue Score (VAS). VAS will be assessed preoperatively as baseline, then daily by patients with a pain scoring diary. This diary will then be collected at time of outpatient followup, 2 weeks after surgery. Patients will also be sent home with oral opioid pro re nata. We expect patients with the new compound ointment to receive better pain control, as reflected on lower VASand less requirement of postoperative oral opioid pro re nata. Other objectives observed will include any postoperative urinary retention, or faecal impaction as likely sequelae to ongoing postoperative pain.