smotic laxatives (eg: lactulose magnesium citrate, polyethylene glycol) work by retaining fluid in the bowel, although prolonged use is hypothesised to cause electrolyte imbalance and side effects can include flatulence and bloating . Jewell and Young (2012) conclude that stimulant laxatives (eg, senna, glycerol suppositories) are more effective than bulk-forming laxatives in pregnancy, as they increase intestinal motility. However anthraquinone stimulant laxatives (eg, dantron) are associated with congenital malformations, therefore are often avoided in pregnancy due to their potential for carcinogenic and genotoxic effects.