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Enema administration

Definition

An enema is the administration of a substance in liquid form into the rectum, either to aid bowel evacuation or to administer medication (Peate [192]) (Figure 6.25). Enemas may also be administered into a colostomy by an appropriately trained nurse (Peate [192]).

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Figure 6.25 Examples of enemas.

Evidence‐based approaches

Rationale

Indications

Enemas may be prescribed for the following reasons:

to clean the lower bowel before surgery, X‐ray examination of the bowel using contrast medium or endoscopy examination
to treat severe constipation when other methods have failed
to introduce medication into the bowel
to soothe and treat irritated bowel mucosa
to decrease body temperature (due to contact with the proximal vascular system)
to stop local haemorrhage
to reduce hyperkalaemia (calcium resonium)
to reduce portal systemic encephalopathy (phosphate enema).

Contraindications

Enemas are contraindicated under the following circumstances (BNF [30]):

in paralytic ileus
in colonic obstruction
where the administration of tap water or soap and water enemas may cause circulatory overload, water intoxication, mucosal damage and necrosis, hyperkalaemia and/or cardiac arrhythmias
where the administration of large amounts of fluid high into the colon may cause perforation and haemorrhage
following gastrointestinal or gynaecological surgery, where suture lines may be ruptured (unless medical consent has been given)
where the patient is frail
where the patient has proctitis.
where the patient has inflammatory or ulcerative conditions of the large colon (for microenemas and hypertonic saline enemas).

Clinical governance

Enema administration must be performed by a practitioner with the appropriate knowledge and skills and where it is within their scope of professional practice to carry out this procedure.

Pre‐procedural considerations

All types of enema need to be prescribed and checked against the prescription before administration. It is essential that the implications and procedure are fully explained to the patient so as to relieve anxiety and embarrassment.

Evacuant enemas

An evacuant enema is a solution introduced into the rectum or lower colon with the intention of it being expelled, along with faecal matter and flatus, within a few minutes. The osmotic activity increases the water content of the stool so that rectal distension follows and induces defaecation by stimulating rectal motility.

The following solutions are often used:

Phosphate enemas with standard or long rectal tubes in single‐dose disposable packs. Although these are often used for bowel clearance before X‐ray examination and surgery, there is little evidence to support their use due to the associated risks and contraindications. Wickham ([247]) highlights the risk of phosphate absorption resulting from pooling of the enema due to lack of evacuation and also the risk of rectal injury caused by the enema tip. Studies have found that if evacuation does not occur, patients may suffer from hypovolaemic shock, renal failure and oliguria. When using this type of enema, it is vital that good fluid intake is encouraged and maintained.
Dioctyl sodium sulphosuccinate 0.1% and sorbitol 25% in single‐dose disposable packs are used to soften impacted faeces.
Sodium citrate 450 mg, sodium alkylsulphoacetate 45 mg and ascorbic acid 5 mg are used in single‐dose disposable packs.

Retention enemas

A retention enema is a solution introduced into the rectum or lower colon with the intention of it being retained for a specified period of time. Two types of retention enema have been most commonly used: arachis oil enemas (which are contraindicated in patients with nut allergies) and prednisolone enemas. These work by penetrating faeces, increasing the bulk and softness of stools. They are classified as stool softeners, but there is little evidence to support the use of this group of laxatives in the treatment of constipation (Woodward [256]).

Procedure guideline 6.21