Interventions for preventing postpartum constipation

What is the issue?

Constipation during the postpartum period is a bowel disorder, characterised by symptoms, such as pain or discomfort, straining, hard lumpy stool, and a sense of incomplete bowel evacuation. Administration of enemas before labour, the ability of women to eat during active labour, and irregular and altered eating habits during the first few days after delivery can each have an influence on bowel movements in the days after giving birth. This is an update of a review first published in 2015.

Why is this important?

Pain and discomfort during defecation can be a source of concern to the new mother, who is recuperating from the stress of delivery, particularly if she has had perineal tears repaired, or has developed haemorrhoids. Postpartum constipation can be stressful because of undue pressure on the rectal wall, leading to restlessness and painful defecation, which may affect the quality of life of the mother and the newborn.

What evidence did we find?

We searched for trials to 7 October 2019. We found no new trials that met our inclusion criteria, thus, we included the initial five trials (involving a total of 1208 women) in this update. Overall, the trials were poorly reported, and four out of five trials were published more than 40 years ago. Four trials compared a laxative with a placebo.

Two trials assessed the effects of laxatives that we now find might be harmful for breastfeeding mothers. One drug, Danthron, has been shown to cause cancer in animals, and the other, Bisoxatin acetate, is no longer recommended when breastfeeding. Therefore, we did not include the results of these trials in our main findings.

The trials did not look at pain or straining on defecation, incidence of constipation, or quality of life, but did assess the time to first bowel movement. In one study assessing the effects of senna, compared to the placebo group, more women in the laxative group had a bowel movement on the day of delivery, and fewer women had their first bowel movement on days 2 and 3, while the results were inconclusive between groups on days 1 and 4 after delivery. More women had abdominal cramps compared to the women in the placebo group, and babies whose mothers received the laxative were no more likely to experience loose stool or diarrhoea. The evidence for all these outcomes is largely uncertain, as we have very serious concerns about risk of bias, and the results are all based on one small study that was conducted at a single institution in South Africa.

One trial compared a laxative plus a stool‐bulking agent (Ispaghula husk) to a laxative only for women who underwent surgery to repair a third degree tear of the perineum (involving the internal or external anal sphincter muscles) that occurred during vaginal delivery. The trial reported on pain or straining on defecation, but did not find a clear difference in the pain score between groups. The trial reported that women who were given laxative plus a stool‐bulking agent were more likely to experience fecal incontinence in the immediate postpartum period. However, the evidence is very uncertain. The trial did not report on any adverse effects on the baby.

What does this mean?

There is not enough evidence from randomised controlled trials on the effectiveness and safety of laxatives during the early postpartum period to make general conclusions about their use to prevent constipation.

We did not identify any trials assessing educational or behavioural interventions, such as a high‐fibre diet and exercise. We need large, high‐quality trials on this topic, specifically on non‐medical interventions to prevent postpartum constipation, such as advice on diet and physical activity.