Did you know pregnancy constipation is one of the most common symptoms reported across all three trimesters, affecting up to 40% of women? Did you also know that the repeated straining that often comes with it can weaken your pelvic floor?
During pregnancy, the pelvic floor is supporting a growing uterus, adapting to shifting pressure through the abdomen and pelvis, and responding to hormonal changes that soften connective tissue in preparation for birth. Add hard stools and regular bearing down into the mix, and it is not difficult to see why constipation can become part of the broader pelvic floor picture.
This does not mean every episode of constipation is causing damage, nor does it mean you need to panic the next time you spend too long in the bathroom. But it is worth understanding what is happening mechanically, because managing constipation well during pregnancy is as much about comfort, as it is about reducing unnecessary strain on the pelvic floor heading into labour and recovery afterwards.
Why pregnancy constipation is so common
Your body undergoes significant change during pregnancy, and the bowel is one of the first things to feel it. Several factors combine to make constipation during pregnancy one of the most frequently reported symptoms across all three trimesters.
Progesterone slows everything down. From early in pregnancy, rising progesterone levels relax smooth muscle throughout the body, including the muscles of the digestive tract. This slows gut motility, meaning food moves through your system more slowly, and more water is absorbed from the stool, making it harder and more difficult to pass.
Your uterus takes up increasing space. As your pregnancy progresses into the second and third trimesters, the growing uterus places direct pressure on the bowel and rectum. This physical compression makes it harder for stool to move through and can contribute to that feeling of incomplete evacuation.
Iron supplements are a common trigger. Iron supplementation is recommended for many pregnant women, but it is well known to cause or worsen constipation. If you started supplementing around the same time your bowel habits changed, that connection is worth noting when you speak with your midwife or GP.
Morning sickness medications can contribute too. Some antiemetics prescribed for nausea and vomiting in pregnancy, particularly in the first trimester, have constipation listed as a side effect. If you have been taking medication for morning sickness, this may be a factor that is easy to overlook.
Eating and drinking habits shift. Nausea can make it hard to eat a varied, fiber-rich diet. Many women eat smaller, less frequent meals or avoid foods that previously triggered nausea. Vomiting reduces overall fluid intake. Drinking less water and consuming less dietary fiber both contribute directly to harder, more difficult-to-pass stools.
In the first trimester, constipation is more likely driven by hormonal changes, iron supplementation, and the effects of nausea medications. By the third trimester, physical compression from the growing baby becomes the dominant factor, and the challenge of getting into a comfortable position on the toilet adds an additional layer of difficulty.
What straining does to your pelvic floor
Your pelvic floor is a group of muscles and connective tissues that span the base of your pelvis, supporting your bladder, bowel, and uterus. During pregnancy, these structures are already under significant load from the growing weight of your baby, placenta, and amniotic fluid.
When you strain to open your bowels, you perform what is known as a Valsalva-type bearing-down effort. This sharply increases intra-abdominal pressure and forces it downward onto the pelvic floor. When this happens repeatedly over days or weeks, while your pelvic floor is simultaneously supporting a growing uterus, the cumulative load becomes meaningful.
Pregnancy compounds this risk in a specific way. The increased hormone production in pregnancy that helps change connective tissues throughout the body to allow a baby to grow, also affects the connective tissue around the pelvic floor to prepare for birth. This connective tissue change means the supporting structures are more pliable than usual, making them more susceptible to stretch injury from repeated downward pressure. The combination of hormone-driven laxity, the mechanical weight of pregnancy, and chronic straining create a level of strain on pelvic structures that would not occur outside of pregnancy.
Over time, this can contribute to:
Pelvic organ prolapse. This is when one or more of the pelvic organs, most commonly the bladder, bowel, or uterus, descend from their normal position and press against or bulge into the walls of the vagina. Prolapse is not always symptomatic, but it can cause heaviness, pressure, or a bulging sensation. It is not an inevitable outcome of pregnancy, but chronic straining is a recognised contributing factor, particularly when the pelvic floor is already under load.
Urinary and faecal incontinence. Repeated downward pressure can stretch and fatigue the pelvic floor muscles over time, reducing their ability to provide support and maintain continence. This is not guaranteed, but it is a risk worth taking seriously, particularly heading into labour.
Hemorrhoids. Straining increases pressure in the veins of the lower rectum, contributing to hemorrhoids. These are extremely common in pregnancy and can worsen after birth, particularly if straining continues in the postnatal period.
It is also worth noting that not all pelvic floor problems during pregnancy come from weakness. Some women develop a hypertonic (tight, overactive) pelvic floor, where the muscles hold tension rather than relax appropriately. A tight pelvic floor can actually make constipation worse, because the muscles around the rectum do not release fully during defecation. If you find that straining is not producing results even with softer stools, or that you experience pelvic pain or tightness, this may be relevant to your situation and is best assessed by a women’s health physiotherapist.
Is your level of straining a problem?
Occasional constipation during pregnancy is extremely common. Needing to strain briefly once in a while is unlikely to create major pelvic floor issues on its own.
The pattern that warrants proactive management is one where straining is frequent, effortful, and ongoing, particularly in the third trimester when the baby’s weight adds the most downward load.
Think of it this way: occasional difficulty is a normal part of pregnancy for many women. Chronic daily straining is a signal that your bowel habits need support, and that your pelvic floor will benefit from some attention before you add to the demands of labour.
When to contact your doctor or midwife
Most pregnancy constipation responds well to dietary and lifestyle measures. However, some symptoms require prompt medical attention rather than self-management.
Contact your GP or midwife if you experience:
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- No bowel movement for more than three to four days despite trying dietary measures
- Blood in the stool or on the toilet paper (beyond minor streaking from haemorrhoids)
- Severe abdominal pain, cramping, or bloating
- Nausea or vomiting alongside constipation
- Any sudden change in bowel habits that feels different from typical pregnancy constipation
These symptoms may indicate something that requires medical review beyond what dietary changes or physiotherapy can address.
Safe pregnancy constipation relief strategies
The good news is that there is a lot you can do to manage constipation during pregnancy safely and effectively.
Increase your fluid intake. Aim for at least two liters of water daily. Hydration is one of the simplest and most effective measures for softening stools. Warm water with lemon in the morning can help stimulate bowel motility for some women.
Adjust your fiber intake gradually. Fiber-rich foods including vegetables, fruits, legumes, wholegrains, and ground flaxseed help add bulk to the stool and draw water into the bowel. Increase fiber gradually to avoid bloating and always pair it with adequate fluid.
Move your body. Gentle movement such as walking, swimming, or pregnancy yoga supports gut motility. Even a short daily walk can make a meaningful difference to bowel regularity.
Speak with your GP or midwife about iron supplementation. If you suspect iron supplements are a significant contributor, your doctor may be able to suggest a different form of iron, such as ferrous gluconate, which some women find more tolerable, or advise on timing and dosage to reduce the impact.
Review nausea medications. If you are still taking antiemetics for morning sickness, ask your doctor or midwife whether your current medication may be contributing to constipation and whether alternatives are available.
Speak to your GP about safe laxative options. Osmotic laxatives such as lactulose and Movicol are considered safe for use in pregnancy and can provide relief when dietary measures are not sufficient. Always check with your healthcare provider before starting any medication during pregnancy.
Correct toileting posture during pregnancy
The position of your body on the toilet matters enormously. In a standard seated position, the puborectalis muscle (which wraps around the rectum) maintains a bend in the anorectal canal, making complete emptying more difficult and increasing the effort required. When you raise your feet and lean forward, you change the angle of this canal to approximate a more natural squatting position, which allows the rectum to straighten and empty with far less effort and strain.
Here is how to do it:
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- Place a footstool (or a small step, a stack of books, or even toilet paper rolls) under your feet while seated on the toilet. A height of roughly 25 to 30 centimetres is ideal.
- Lean forward so your forearms rest on your thighs and your back has a gentle forward lean.
- Relax your abdomen, allow your belly to drop forward, and breathe out slowly.
- Rather than pushing, try a gentle hum or a low exhalation. This helps activate the correct muscle coordination for bowel emptying without forcing.
- Never hold your breath and strain with a closed throat. This is the pattern that creates the most downward pelvic floor pressure.
As your bump grows in the third trimester, this posture may feel more awkward, but it remains worth attempting. You may need to widen your knees slightly to make room for your abdomen.
If you would like more detail on correct bowel emptying technique, read our guide on how to poo properly.
Pelvic floor exercises during pregnancy
Pelvic floor exercises can absolutely be useful during pregnancy, but they are often oversimplified online.
A pelvic floor needs both strength and the ability to relax properly. Focusing only on squeezing and tightening is not always helpful, particularly for women who already carry a lot of tension through the pelvic floor.
In some cases, an overactive pelvic floor contributes to constipation because the muscles do not release effectively during bowel emptying. More Kegels are not automatically the answer.
This is where assessment matters. A women’s health physiotherapist can determine whether the pelvic floor is weak, tight, poorly coordinated, or a combination of all three, and tailor management accordingly.
Protecting your pelvic floor after birth
Many women are surprised to discover that constipation does not automatically resolve after delivery. In fact, for many women it continues or temporarily worsens in the days and weeks following birth.
Several factors contribute to postnatal constipation. After a vaginal birth, perineal soreness and swelling can create a fear of bowel movements that leads to voluntary holding and increased straining when the urge finally cannot be ignored. After a caesarean section, opioid-based pain relief commonly prescribed in the immediate postoperative period significantly slows bowel motility. Breastfeeding increases your body’s fluid demands, meaning dehydration can develop quickly if you are not consciously increasing your intake.
The immediate postnatal period is also when prolapse and haemorrhoid risk is elevated. If you have been straining throughout pregnancy, your pelvic floor arrives at this phase already under load, and the physical demands of birth add to that. Prioritising correct toileting posture, adequate hydration, fiber intake, and gentle movement in the first weeks after birth will directly protect a pelvic floor that may have been working hard for months.
If you are in the early postnatal period and struggling with constipation or pelvic heaviness, this is exactly the time to seek physiotherapy support rather than wait.
When to see a women’s health physiotherapist
If constipation is becoming persistent, painful, or associated with pelvic floor symptoms, it is worth getting assessed rather than trying to manage it indefinitely with more fiber and optimism.
A women’s health physiotherapist can help with:
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- pelvic floor assessment
- bowel-emptying mechanics
- toileting posture
- pelvic floor relaxation and strengthening
- prolapse management
- postnatal recovery planning
You do not need to wait until symptoms become severe to seek support. In many cases, addressing bowel habits and pelvic floor mechanics early is far easier than trying to unwind months of strain later on.
Support beyond diet and exercise changes
Constipation during pregnancy is common, but that doesn’t make it easy to live with. If it’s affecting your mood or how you’re coping day to day, that’s worth talking about too. Our Women’s psychologist works with women through the physical and emotional load of pregnancy, and can support you with the parts that diet and lifestyle changes don’t fix on their own.
Book an appointment with North West Healthy Women
If constipation during pregnancy is becoming a regular issue, or you are starting to notice symptoms like pelvic heaviness, pressure, or leaking, it’s worth getting assessed sooner rather than later.
A women’s health physiotherapist can identify whether your pelvic floor is under excessive strain, assess how well your muscles are coordinating during bowel emptying, and give you practical strategies to reduce pressure before labour and recovery add even more demand.
Book an appointment with our women’s health physiotherapy team to get a personalised assessment and management plan tailored to your stage of pregnancy and symptoms.
If pregnancy constipation is affecting your daily life or you are concerned about what straining might be doing to your pelvic floor, we would love to help. Reach out to us directly to make an appointment, and let us help you feel more comfortable and confident in your body, both now and after your baby arrives.
Frequently Asked Questions
Is it safe to use laxatives for pregnancy constipation?
Certain laxatives are considered safe during pregnancy. Osmotic laxatives such as lactulose and Movicol (polyethylene glycol) are commonly recommended by GPs and midwives. Stimulant laxatives such as senna are generally used with more caution and only on medical advice. Always speak with your healthcare provider before starting any laxative during pregnancy, as the safest option will depend on your individual circumstances.
Can straining cause premature labour?
There is no strong evidence that occasional straining triggers preterm labour. The main concerns with chronic straining during pregnancy relate to pelvic floor strain, haemorrhoids, and prolapse risk rather than uterine stimulation. However, if you are experiencing any tightenings alongside constipation, discuss this with your midwife.
Will my pelvic floor recover after birth?
For most women, yes. The pelvic floor has a significant capacity for recovery with the right support. Early physiotherapy assessment after birth, attention to correct technique in the postnatal period, and a structured pelvic floor rehabilitation program make a substantial difference to recovery outcomes.
How does iron supplementation affect constipation during pregnancy?
Iron is essential during pregnancy, particularly in the second and third trimesters, but it is one of the most common causes of constipation in pregnant women. Different forms of iron vary in their impact. Speak with your GP or midwife about whether your current iron supplement could be contributing, and whether a different formulation or approach might offer better tolerance without compromising your iron levels.
Can I do anything about constipation in the first trimester if morning sickness is making it hard to eat and drink normally?
Yes. Focus on small, frequent sips of fluid throughout the day rather than large volumes at once. Even small amounts of dietary fiber, such as a small handful of dried fruit or a slice of wholegrain bread, can help. Speak with your midwife about whether your nausea medication could be contributing and what alternatives exist. A physiotherapist can also advise on gentle strategies that are practical during the first trimester when symptoms are most limiting.