The technique of injection is as follows; the patient is put in the left lateral position. The proctoscope is lubricated and inserted into the anal canal with the obturator in place. The patient is requested not to squeeze against the proctoscope. The angle of entry of the proctoscope should be such that it will travel along the normal line of the anal canal, which usually runs along a line connecting the anal verge towards the patients umbilicus. If there is doubt about the normal line of the patients canal, this may be judged from a digital examination.
The correct place to inject the phenol in almond oil is into the submucosa, a small volume of the solution is injected at least 1.5 cm above the dentate line. If blanching of the mucosa occurs the site of injection is too superficial. If there is no rise in the mucosa then the injection is too deep. The correct location of the site of injection is well above the dentate line, you should see a bleb appearing but the mucosa should not blanch. The problem with injecting too superficially is that the mucosa will necrose and slough, so the patient will develop an ulcer and may suffer pain, bleeding and sepsis. The problem with injecting too deeply is that the patient may get perirectal fibrosis and sepsis, the uretra may be damaged and injection into the prostate of seminal vesicle may result in priaprism, sepsis and impotence.
Particular care should be taken to avoid injecting anteriorly because of the close relation of the rectum to the prostate gland. Surrounding the prostate are the parasympathetic ganglia that are responsible for erection. Damage to these ganglia may result in impotence. Do not inject anteriorly.
It has been recommended that 3-5 ml should be injected into each haemorrhoid. I personally favour a smaller amount.
The patient should not experience severe pain. If they do stop injecting;