The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [196]
Over recent years, international criteria (the Rome Criteria) have been developed and revised (Longstreth et al. 2006) which can help to more accurately and consistently define constipation. According to the new Rome III Criteria, an individual who is diagnosed with constipation should report having at least two of the following symptoms within the last 3 months where those symptoms began at least 6 months prior to diagnosis (Longstreth et al. 2006, Norton 2006).
Straining for at least 25% of the time.
Lumpy or hard stool for at least 25% of the time.
A sensation of incomplete evacuation for at least 25% of the time.
A sensation of anorectal obstruction or blockage for at least 25% of the time.
Manual manoeuvres used to facilitate defaecation at least 25% of the time (e.g. manual evacuation).
Less than three bowel movements a week.
Also, in such patients, loose stools are rarely present without the use of laxatives.
It is important to recognize that although the Rome Criteria are the most used definition of constipation, their application to cancer and palliative care patients has its limitations (Stevens et al. 2008). The rationale for this is that many cancer and palliative care patients have constipation which is caused by a physical process or a drug so they do not have functional constipation. Also, many in this group of patients require treatment before 12 weeks.
The myth that daily bowel evacuation is essential to health has persisted through the centuries. It is thought that less than 10% of the population have a bowel evacuation daily (Edwards et al. 2003). This myth has resulted in laxative abuse becoming one of the most common types of drug abuse in the Western world. The annual cost to the NHS of prescribing medications to treat constipation is in the region of £45 million (DH 2005b).
An individual’s bowel habit is dictated by their diet, lifestyle and environment, and the notion of what is a ‘normal’ bowel habit varies considerably. Studies have revealed that in the USA and UK, 95–99% of people pass at least three stools per week (Ehrenpreis 1995) and ‘normal’ bowel movement has been defined as ranging between three times a day and three times a week (Nazarko 1996). Given that there is such a wide normal range, it is important to establish the patient’s usual bowel habit and the changes that may have occurred. Many patients are too embarrassed to discuss bowel function and will often delay reporting problems, despite the sometimes severe impact these symptoms have on their quality of life (Cadd et al. 2000). Generally complaints will be either that the patient has diarrhoea or is constipated. These should be seen as symptoms of some underlying disease or malfunction and managed accordingly. The nurse’s priority is to effectively assess the nature and cause of the problem, to help find appropriate solutions and to inform and support the patient. This requires sensitive communication skills to dispel embarrassment and ensure a shared understanding of the meanings of the terms used by the patient (Smith 2001).
Pharmacological support
Laxatives
Laxatives can be defined simply as substances that cause evacuation of the bowel by a mild action (Mosby 2006). A laxative with a mild or gentle effect is also known as an aperient and one with a strong effect is referred to as a cathartic or a purgative. Purgatives should be used only in exceptional circumstances, that is, where all other interventions have failed, or when they are prescribed for a specific purpose. The aim of laxative treatment is to achieve comfortable rather than frequent defaecation and, wherever possible, the most natural means of bowel evacuation should be employed, with preference given to use of oral laxatives where appropriate (Fallon and O’Neill 1997, Perdue 2005). The many different types of laxatives available may be grouped into types according to the action they have (see Table 6.3).
Table 6.3 Types of laxative
Type of laxative