PROCEDURES - Rigid Sigmoidoscopy

1. Definition

Rigid Sigmoidoscopy is the endoscopic examination of the the rectum to the recto-sigmoid junction using a sigmoidoscope passed through the anal canal. It requires direct vision by the practitioner

Proctoscopy is the endoscopic examination of the anal canal using a proctoscope.

Diagnostic - Allows direct visualisation of pathology as well as visual and tissue diagnosis via biopsy.

Therapeutic - Allows haemorrhoids to be treated
 
2. Indications

Any symptom which suggests colonic neoplasia
To investigate inflammatory bowel disease
For taking biopsies of any pathology within direct visualisation
Before any ano-rectal operation/procedure
Proctoscopy - to treat/band haemorrhoids
 
3. Complications

Perforation of the colon - the main risk. Can be due to
Mechanical reasons such as pushing the tip of the colonoscope against weak sites of the colon wall such as diverticula, areas of inflammation or just before strictures.
Pneumatic reasons - over inflation with air
Risk is increased with poor bowel preparation
Bleeding - Delayed bleeding may occur following banding of haemorrhoids, and this can occur up to one week after the procedure. Delayed bleeding usually stops on its own but in some severe cases laparotomy/colonoscopy may be required.
Infection - can lead to a gram negative bacteraemia
 
4. The Sigmoidoscope and Proctoscope

The rigid sigmoidoscope with obturator (top)

The light source, bellows and eyepiece

The Sigmoidoscope set up
Light source on
obturator placed through eye piece
Bellows to hand
 
The Proctoscope
Introducer in place
Light source is attached to blue component

5. Procedure

As the technique is usually performed in the outpatients department, no sedation or bowel preparation is usually given.
However for good views a suppository should be given prior to the examination
Positioned in the left lateral decubitus position with buttocks at/over the edge of the couch
Couch then raised to comfortable level for the physician to perform the examination
PR performed - ensures there is no obstruction to the scope as it is passed
The sigmoidoscope must be lubricated prior to insertion either with water or lubricating jelly
Tip of the obturator and scope is then passed in to the anal canal in the direction of the umbilicus
Once the scope has passed through the anal canal the obturator is removed and the eyepiece secured
The bellows are used at this stage and the scope is only advanced when the lumen can be visualised to ensure safe progression of the scope
The goal is to visualise the rectum to the recto-sigmoid junction (15-17cm from the anal verge)
However the procedure may not be completed due to
faecal loading and therefore poor visualisation
Pain experienced by the patient
Biopsies can taken for histology
As the scope is withdrawn it is essential to view the mucosa
The exact technique applies for proctoscopy except banding of haemorrhoids may be performed using the proctoscope