Botulin toxin (Botox) can be injected into the internal anal sphincter causing a temporary paralysis. This can lead to healing of a chronic anal fissure in 50 – 80 %. The advantage of botox is that it is simple and safe. It is usually done under sedation or a general anaesthetic as the injection itself is quite painful.
What to expect post-operatively
If no other procedure is done with the botox injection, then there should be no extra pain after the procedure. The fissure pain may continue as the botox takes a few days to start working and can take up to a month to completely settle.
A high fibre diet is important. It may be usually to take a fibre supplement such as Metamucil or benefibre.
It is very important to keep the bowel motions soft. Taking a laxative such as movicol (1-2 sachets daily) may be needed to achieve this. Constipation and straining should be avoided. Similarly, too frequent and very loose motions should be avoided.
The fissure wound should be kept clean by either showering or having a salt bath after each motion. Using baby wipes is also a good way of maintaining hygiene. Continue to use rectogesic (0.2%) or nifedipine (0.3%) ointment 3 times a day until the pain has subsided.
Most patients have no complications with botox. Very occasionally, one might experience some minor faecal incontinence (loss of control) but this is not permanent as the botox effect wears off. Urinary retention bleeding and infection are very rare. The recurrence rate after botox is much higher than with a sphincterotomy with up to 50% having recurrence over the 1st 2 years.