Constipation in the third trimester: what to know

Pregnancy hormones can slow the bowel, and the growing womb can affect the space available for the intestines. Iron supplements, reduced activity, nausea, and not drinking enough can add to hard stools, straining, bloating, or a feeling that the bowel has not emptied fully.

Constipation does not automatically mean another disease. However, a clinician may consider medicines, thyroid problems, irritable bowel symptoms, or another bowel condition when constipation is new, severe, persistent, or accompanied by other changes.

Drink fluids regularly, increase fibre gradually through vegetables, fruit, whole grains, beans, and pulses, and take gentle movement if your maternity team says it is safe. Allow time for the toilet, respond to the urge, and use a footstool to keep your knees comfortably higher than your hips.

If iron seems to worsen constipation, do not stop it by yourself. Ask whether the preparation or timing can be changed. A clinician or pharmacist can recommend a pregnancy-suitable laxative when food, fluids, and movement are not enough; avoid herbal remedies or frequent stimulant use without advice.

Contact your maternity team or doctor for constipation that does not improve, repeated vomiting, inability to pass gas, worsening abdominal swelling, or significant pain. Seek urgent help for severe or constant abdominal pain, blood in the stool, black stools, fainting, or signs of dehydration such as very little urine and marked dizziness.

Ask how much fibre and fluid suit you, whether your iron supplement could be adjusted, and which laxative is appropriate if needed. Mention abdominal pain, vomiting, bleeding, thyroid disease, or a change in your usual bowel pattern.