The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [199]
Positioning
Patients should be advised not to ignore the urge to defaecate and to allow sufficient time for defaecation (Norton 1996a). It is important that the correct posture for defaecation is adopted; crouching or a ‘crouch-like’ posture is considered anatomically correct (Taylor 1997) and the use of a footstool by the toilet may enable patients to adopt a better defaecation posture (Edwards et al. 2003, NICE 2007, Norton 1996a, Taylor 1997) (see Figure 6.13). The use of the bedpan should always be avoided if possible as the poor posture adopted while using a bedpan has been shown to cause extreme straining during defaecation (Taylor 1997). Where possible, patients should be supported to get to a bathroom.
Exercise
Where possible, patients should be encouraged to increase their level of exercise; physical activity has been found to have a positive effect on peristalsis, particularly after eating (Thompson et al. 2003). Therapies such as homoeopathy and reflexology can also be utilized (Edwards et al. 2003, Emly et al. 1997, Rankin-Box 2000).
However, overall, laxatives are the most commonly used treatment for constipation (Table 6.4). In general, they should be used as a short-term measure to help relieve an episode of constipation as long-term use can perpetuate constipation and a dependence on laxatives can develop (Butler 1998). However, in cancer and palliative care patients where drugs such as opioids may need to be maintained then laxative therapy may need to continue for longer periods of time.
Table 6.4 Classification of laxatives
Enemas
Definition
An enema is the administration of a substance in liquid form into the rectum, either to aid bowel evacuation or to administer medication (Higgins 2006).
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 before endoscopy examination.
To treat severe constipation when other methods have failed.
To introduce medication into the system.
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.
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 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).
Frailty.
Proctitis.
The use of microenemas and hypertonic saline enemas in patients with inflammatory or ulcerative conditions of the large colon.
Recent radiotherapy to the lower pelvis unless medical consent has been given (Davies 2004).
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 (Barrett 1992, Roe 1994).
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. Davies (2004) and Bowers (2006) highlight 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