Interventions for treating postpartum constipation
Abstract
Background
Constipation is a functional bowel disorder that can reduce quality of life in the puerperium period. The diagnosis of postpartum constipation is both subjective and objective. It is characterised by symptoms such as pain or discomfort, straining, hard lumpy stools and a sense of incomplete bowel evacuation. Haemorrhoids, pain at the episiotomy site, effects of pregnancy hormones and hematinics used in pregnancy can increase the risk of postpartum constipation. Although a high fibre diet and increased fluid intake is encouraged to assist defecation in the puerperium, pain‐relieving drugs and laxatives are common drugs of choice to alleviate constipation. However, the effectiveness and safety of laxatives on the nursing mother need to be ascertained.
Objectives
To evaluate the effectiveness of interventions for treating postpartum constipation.
Search methods
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 March 2014), the metaRegister of Controlled Trials, the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov), the Australian New Zealand Clinical Trials Registry (ANZCTR), the World Health Organization International Clinical Trials Registry platform (ICTRP), the ProQuest database, Stellenbosch University database and Google Scholar (28 March 2014). We also searched the reference lists of potentially relevant studies identified by the search, reviewed articles for relevant trials and contacted experts to identify any additional published or unpublished trials (10 April 2014).
Selection criteria
All randomised controlled trials comparing any intervention for the treatment of postpartum constipation to another intervention, placebo or no intervention.
Interventions could include laxatives, surgery, as well as educational and behavioural interventions.
Data collection and analysis
Two review authors independently screened the results of the search to select potentially relevant studies using pre‐designed eligibility inclusion criteria. Discrepancies were resolved through discussion. We did not identify any studies for inclusion.
Main results
We did not identify any studies that met our inclusion criteria. We excluded nine studies.
Authors' conclusions
We could not make explicit conclusions on interventions for treating postpartum constipation because we found no studies for inclusion in this review. Rigorous and well‐conducted large randomised controlled trials aimed at treating postpartum women diagnosed with constipation would be beneficial. These trials should also address the criteria for administering the intervention (time and stage of a diagnosis of postpartum constipation), and the safety and effectiveness of such interventions.
PICO
Plain language summary
Interventions for treating postpartum constipation
Women may experience constipation during the postpartum period. Consipation is defined as a functional bowel disorder that is characterised by pain and discomfort, straining, hard lumpy stools and a sense of incomplete bowel evacuation. Haemorrhoids, pain at the episiotomy site, effects of pregnancy hormones and iron supplementation can increase the risk of postpartum constipation; as can damage to the anal sphincter or pelvic floor muscles during childbirth. It is a source of concern to the new mother who is recovering from the stress of delivery. The discomfort does not only affect the mother's health, but also impacts on the new baby's well‐being, since it needs most of the mother's attention at this time.
A high fibre diet and increased fluid intake can prevent constipation in the puerperium period. Pain‐relieving drugs and laxatives are common drugs in relieving constipation. Laxatives are grouped according to their function, as bulk‐forming laxatives (such as bran, psyllium and methycellulose) that increase the weight and water content of the stool to facilitate bowel movement; osmotic laxatives (such as lactulose and polyethylene glycol (PEG)) that add water to the colon to improve bowel movement; and stimulant laxatives (such as bisacodyl, castor oil and senna), which act by irritating the intestinal wall. Stool softeners lubricate stools to improve their passage.
This review aimed to evaluate the effectiveness and safety of the available interventions to treat postpartum constipation. We did not find any randomised controlled trials where women diagnosed with postpartum constipation were treated with different interventions. We are thus unable to make any conclusions. There is a need for large trials to evaluate the effectiveness and safety of interventions (such as laxatives, surgery, as well as educational and behavioural interventions) during the postpartum period.
Authors' conclusions
Background
Description of the condition
Postpartum constipation is a common condition affecting postpartum mothers (Cheng 2008). Traditionally, the postpartum period starts from childbirth and includes the following six weeks during which the mother's body returns to the pre‐pregnant state (Liu 2009). Evidence from studies however, suggests that a great number of women experience constipation up to three to six months postpartum and in some individuals it may even persist to 12 months following delivery (van Brummen 2006). Constipation can be defined as difficult bowel evacuation characterised by straining, lumpy or hard and dry stools, sensation of incomplete evacuation, anorectal obstruction, or the use of manual manoeuvres (Higgins 2004). According to the Rome III criteria (Drossman 2006), chronic functional constipation in adults is defined as having two or more of the following symptoms for at least three months: straining in at least 25% of defecations, lumpy or hard stools in at least 25% of defecations, sensation of incomplete evacuation in at least 25% of defecations, sensation of anorectal obstruction or blockade in at least 25% of defecations, the use of manual manoeuvres (e.g. digital evacuation, support of the pelvic floor) to facilitate at least 25% of defecations, fewer than three defecations per week; loose stools are rarely present without the use of laxative (Lee‐Robichaud 2011). Since the pelvic floor muscles play an important role in defecation, injury to the levator ani muscle during childbirth may lead to constipation in the postpartum period (Shafik 2002). Other studies found that forceps delivery, prolonged second stage of labour and higher child birthweight could result in anal sphincter injury resulting in postpartum constipation (Sultan 1993). Haemorrhoids are also a common anorectal medical condition in pregnancy and the postpartum period causing painful defecation and swelling at the anus resulting in constipation. Some other specific postpartum factors such as breastfeeding and obstetric events seem to affect bowel function during the postpartum period (Bradley 2007).
The prevalence of postpartum constipation was estimated to be 24% at three months postpartum by Bradley 2007. The same study found that constipation (as classified by the Rome II criteria Drossman 2000), affects up to 25% of women throughout pregnancy and at three months postpartum. Another study (Ponce 2008) reports a prevalence of constipation in the puerperium as 41.8% by self‐report and 24.7% as classified by the Rome II criteria (Drossman 2000). Defecation symptoms in early pregnancy (12 weeks' gestation) in women with a lower body mass index (BMI) was also found to be associated with constipation at 12 months after childbirth (van Brummen 2006).
Constipation is a functional bowel disorder and can significantly reduce the quality of life in adults (Daisy 2002). Postpartum constipation is identified mostly by symptoms such as pain or discomfort and bowel habits and stool characteristics, which makes the diagnosis both subjective and objective. Therefore, the use of time transit (Bristol Stool Form Scale) and Rome criteria is necessary for clinical diagnosis, evidence‐based management and research (Longstreth 2006). The causes of constipation can be classified as lifestyle‐related, disease‐related, or drug‐induced (Candy 2011).
Description of the intervention and how the intervention might work
Appropriate interventions for the treatment of constipation depend on the cause (Candy 2011). Although interventions specifically tailored for postpartum constipation treatment are few, some of the interventions targeting constipation in general can also be used to treat postpartum constipation. Lifestyle modifications that include adequate fibre (such as fruits, vegetables, for example cucumber, and soup) (Liu 2009) and water and fluids (Candy 2011) in the diet can help to relieve the symptoms and prevent recurrences of constipation. Soluble fibre (which helps soften the stools) and insoluble fibre (which adds bulk to the stools) both promote regular bowel movements (Balch 2010). Laxatives can be used to treat constipation and are grouped in the following categories according to their function: bulk‐forming laxatives, osmotic laxatives, stimulant laxatives, faecal softeners and lubricants (Candy 2011). Bulk‐forming laxatives (such as bran, psyllium, and methylcellulose) work by increasing the weight and water content of the stools and thereby facilitate the peristaltic movement of stools (Balch 2010). Osmotic laxatives (such as lactulose and polyethylene glycol (PEG)) add water into the colon, which then improves bowel movement (NIH 2007). A recent Cochrane review reported the treatment effect of two osmotic laxatives (lactulose versus PEG) for chronic constipation and concluded that PEG is superior to lactulose in improving the form and frequency of the stool, relieving abdominal pain, and in decreasing the need for additional products (Lee‐Robichaud 2011). Stimulant laxatives (such as bisacodyl, castor oil, and senna) ease the bowel movement by irritating the intestinal wall (Balch 2010). Stool softeners work by lubricating stools, thereby improving the passage of stools through the intestines (NIH 2007). Surgical interventions can also be used to treat constipation, for example, surgical repair of anorectal problems such as rectal prolapse (NIH 2007). Studies have also reported on the efficacy of acupuncture and Chinese herbal medicine as an intervention in treating postpartum constipation (Cheng 2009). A randomised controlled trial (Eogan 2007) found that administration of a stool‐bulking agent in addition to a laxative is not more effective in preventing constipation during the postpartum period for women who have sustained anal sphincter injury at vaginal delivery.
Why it is important to do this review
The postpartum period is an important stage in a mother's life, and for her newborn baby. Considering the morbidity effects of constipation, cost and negative impact on quality of life (Peppas 2008), an evaluation of the effectiveness and safety of available interventions for the treatment of postpartum constipation is necessary. Although a number of systematic reviews on constipation have been published (for example, Gordon 2011; Higgins 2004; Jewell 2001; Lee‐Robichaud 2011; Mugie 2011; Peppas 2008), currently there is no systematic review published on interventions for the treatment of postpartum constipation specifically. Although there are some interventions for the treatment of general constipation, not all of them are suitable for use in the postpartum period. Furthermore, cultural beliefs about the postpartum period may result in some lifestyles with certain prescribed diets and lack of exercise, both of which may promote postpartum constipation (Liu 2009). A systematic review is therefore necessary to summarise and evaluate the effectiveness and safety of various interventions for the treatment of postpartum constipation.
Objectives
To evaluate the effectiveness and safety of interventions for the treatment of postpartum constipation.
Methods
Criteria for considering studies for this review
Types of studies
All randomised controlled trials (including those using a cluster‐randomised design) comparing any intervention for the treatment of postpartum constipation versus another intervention or placebo or no treatment were eligible for inclusion. Studies presented only as abstracts were eligible for inclusion. Studies using a cross‐over design were not eligible for inclusion because the physiological condition of women during the first month postpartum might not be the same as six months after childbirth.
Types of participants
Postpartum women (from day one to six months postpartum) diagnosed with postpartum constipation (using pre‐specified criteria (Rome and Bristol Stool Form Scale) and self‐report). We also planned to include postpartum women with co‐morbidities, e.g. sphincter injuries.
The six months criterion was used because constipation is a problem that may last longer than six weeks following delivery, which is the usual postpartum period.
Types of interventions
Intervention
Any intervention for the treatment of postpartum constipation including laxatives, surgery, as well as educational and behavioural interventions.
Control
Any other intervention for the treatment of postpartum constipation, or placebo or no treatment.
Types of outcome measures
Primary outcomes
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Pain or straining on defecation.
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Participant‐reported relief of constipation symptoms.
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Stool frequency.
Secondary outcomes
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Stool consistency (e.g. Bristol Stool Scale): The Bristol Stool Form Scale is a formal research tool used to evaluate the effectiveness of treatments for gastrointestinal tract disease as well as in clinical communication. It assists the patients to report on stool consistency. It is used to categorise stool into seven types according to stool consistency (Lewis 1997).
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Use of additional products (e.g. alternative laxative agents, enemas).
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Relief of abdominal pain.
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Change in quality of life.
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Adverse effects caused by the intervention, including:
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nausea or vomiting;
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pain;
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flatus;
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diarrhoea;
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faecal incontinence.
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Search methods for identification of studies
Electronic searches
We contacted the Trials Search Co‐ordinator to search the Cochrane Pregnancy and Childbirth Group’s Trials Register (28 March 2014).
The Cochrane Pregnancy and Childbirth Group’s Trials Register is maintained by the Trials Search Co‐ordinator and contains trials identified from:
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monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL);
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weekly searches of MEDLINE;
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weekly searches of Embase;
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handsearches of 30 journals and the proceedings of major conferences;
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weekly current awareness alerts for a further 44 journals plus monthly BioMed Central email alerts.
Details of the search strategies for CENTRAL, MEDLINE and Embase, the list of handsearched journals and conference proceedings, and the list of journals reviewed via the current awareness service can be found in the ‘Specialized Register’ section within the editorial information about the Cochrane Pregnancy and Childbirth Group.
Trials identified through the searching activities described above are each assigned to a review topic (or topics). The Trials Search Co‐ordinator searches the register for each review using the topic list rather than keywords.
In addition, we searched the following (28 March 2014) to identify relevant trials:
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The metaRegister of Controlled Trials.
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The US National Institutes of Health Ongoing Trials Register (www.clinicaltrials.gov).
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The Australian New Zealand Clinical Trials Registry (ANZCTR).
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The World Health Organization International Clinical Trials Registry platform (ICTRP).
We also searched the ProQuest database, Stellenbosch University database and Google scholar (28 March 2014). See Appendix 1 for search terms used.
Searching other resources
Reference lists and correspondence
We searched the reference lists of potentially relevant studies identified by the search and reviewed articles for relevant trials. We also contacted experts in the field of constipation and obstetrics to identify any additional published or unpublished trials.
We did not apply any date or language restrictions.
Data collection and analysis
The methods of data collection and analysis are based on the standard methods text of the Cochrane Pregnancy and Childbirth Group.
Selection of studies
Two review authors, Eunice Turawa (ET) and Alfred Musekiwa (AM), independently screened the results of the search to select potentially relevant studies. Applying eligibility criteria using a pre‐designed eligibility form based on the inclusion criteria, we excluded duplicates and studies that were not relevant to the review. We retrieved the full‐text articles of potentially relevant studies. Each of the articles was scrutinised to ensure that multiple publications of the same trial were included only once. Where eligibility was unclear, we sought clarification from the trial authors and re‐assessed the corresponding articles. We resolved any disagreement through discussion and consultation with the third review author (Anke Rohwer (AR)). We excluded studies that did not meet the inclusion criteria and stated the reasons in the Characteristics of excluded studies table.
Data extraction and management
We did not identify any studies that met our inclusion criteria and thus were unable to perform data extraction and analysis. We have outlined the methods to be used in future updates of this review in Appendix 2 and Appendix 3.
Results
Description of studies
Characteristics of excluded studies.
Results of the search
We summarised the search results in detail in Figure 1. The Cochrane Pregnancy and Childbirth Group’s Trials Register retrieved 11 trial reports; Stellenbosch University database, one report; Google Scholar, 11,500 reports, Clinical Trials Registries, two reports; screening study references yielded one extra trial making a total of 11,515 trial reports. After deduplication, we screened 11,501 reports resulting in nine potentially relevant reports.
Study flow diagram
Scrutinising the full texts of the remaining nine trials (two non‐English studies inclusive) resulted in none of the trials meeting our eligibility criteria. Nine trials (Du 2008; Duncan 1957; Diamond 1968; Goplerud 1967; Mundow 1975;Nardulli 1995; Raatikainen 1974; Shelton 1980; Zuspan 1960) were excluded for the reasons displayed in the Characteristics of excluded studies.
Included studies
We could not include any trials because none of the trials met the pre‐specified inclusion criteria.
Excluded studies
We excluded nine trials (Du 2008; Duncan 1957; Diamond 1968; Goplerud 1967; Mundow 1975;Nardulli 1995; Raatikainen 1974; Shelton 1980; Zuspan 1960).The most common reason for exclusion was that study design was not randomised trial (Du 2008; Duncan 1957; Goplerud 1967; Mundow 1975;Nardulli 1995; Raatikainen 1974; Zuspan 1960). For Diamond 1968 and Shelton 1980, the participants were not clinically diagnosed with postpartum constipation. See the Characteristics of excluded studies.
Risk of bias in included studies
There are no included studies.
Effects of interventions
There are no included studies in this review.
Discussion
Summary of main results
There are no included studies in this review.
The objective of this review was to assess the effectiveness and safety of different forms of interventions for treating postpartum constipation. A comprehensive electronic search without language restrictions of potential trials was conducted and nine trial reports identified. However, we did not find any trials of postpartum women clinically diagnosed with constipation and subsequently treated for constipation. We therefore excluded all nine studies.
Potential biases in the review process
We sought published and unpublished trials irrespective of languages. Translators were involved to assist in studies published in foreign languages. At least two review authors independently assessed trials for inclusion in the review.
Study flow diagram
