Pregnancy is a time when women are susceptible to bowel habit perturbations. The purpose of this study was to provide new baseline data for a range of bowel habit parameters. Prospective 7-day bowel habit diaries were completed during each of the three trimesters of pregnancy and after birth. Sensations of incomplete evacuation and time spent defecating were significantly increased during all three trimesters of pregnancy compared with after birth (P < 0.05). Symptoms of urgency were higher in nonlactating mothers (41% of occasions) compared with lactating women (17% pf occasions) (P=0.07). This study has confirmed the importance of investigating a range of bowel habit parameters during and after pregnancy-investigation of constipation per se may obscure changes in individual bowel habit parameters.