Why your poop is different during your period
Is your poop different during your period? Yes, period poop is really a thing…but why? Let’s talk about how your hormones affect symptoms like gas, bloating, constipation and even diarrhea. We’ll cover how your period might make your irritable bowel syndrome (IBS) symptoms worse and how to eat to ease the dreaded period poops.
As a digestive health dietitian, I talk a lot about poop and how you can regulate digestion with diet (especially foods rich in fibre) and lifestyle (water and movement!). But, there are some times that weird poops aren’t just about what you’re eating or your stress levels: it’s your hormones. Now, it’s important to know that it is 100% normal to have variations in your gut health. If your menstrual cycle tweaks your gut routine a bit and it doesn’t bother you, then no need to overanalyze it. Keep these tips in your back pocket for when you need them. However, if you are concerned about the severity of symptoms always be sure to talk to your doctor before seeking solutions.
What causes period poop?
Although we typically talk about the body in isolated systems such as the digestive system or reproductive system, everything in the body is connected. So, what is originating in one part of your body – say, your ovaries – can affect what is happening in another part of your body (like your colon!). Changes to your digestive function around your period are exceedingly common. In one Canadian trial, 73% of healthy subjects reported GI issues premenstrually and 69% reported symptoms during their period.
Sex hormones such as estrogen and progesterone can alter digestive motility, which is the way that your gut moves. For example, as progesterone rises in the luteal phase of menstrual cycle, it can slow down motility and cause bloating and constipation. When you’re constipated, gas can smell a bit more as it has to literally squeeze past the poop, picking up some of its smell. Kinda icky, but good to know. Progesterone can also trigger cravings and increased appetite in the days before your period, leading you to eat larger amounts of rich or hyper-processed foods than you usually eat. If these foods are higher in salt and lower in fibre, they can exacerbate constipation and smelly gas further.
When progesterone has fallen and your period begins, you may find that diarrhea or loose stools take hold for a couple of days. The reason for this is that your body produces prostaglandins, which help contract the uterine lining to initiate your period. This prostaglandin release is also thought to alter contractions in the digestive tract, which, in the absence of slow-your-roll progesterone, may lead to loose stools or diarrhea.
Does your IBS get worse around your period?
While not all adults with IBS report symptoms changes around menstruation, many do. Estrogen and other sex hormones can interact with your digestive function and your gut-brain communication in multiple ways, for example, increasing the visceral sensitivity of your gut nervous system, which can lead to increased feelings of pain and discomfort. Combined with the ways that sex hormone fluctuations can directly influence motility, leading to increased constipation or diarrhea, you may find that your IBS symptoms are more intense at certain times in your cycle.
Low FODMAP diet for IBS
If you have irritable bowel syndrome that has responded well to a low FODMAP diet in the past, you may find it helpful to eat low FODMAP for 3-4 days around your period if your symptoms of gas, bloating and/or diarrhea are challenging. The advice below may also be of benefit. Every body is different, stick with what works for YOU.
What to eat help prevent constipation before your period
In the few days before your period, you may find yourself craving certain foods like chocolate or nachos or whatever – you can partially thank progesterone for that. These foods may be higher in fat (slows motility), salt (dehydrates) and lower in fibre (slows motility). And, what you eat has a fairly immediate impact on how your gut moves.
That being said, I’m not really a fan of fighting against your body’s signals. Just try telling me I can’t have chips when I want chips, I dare you, ha ha! Instead the goal is both/and instead of either/or. Honour what your body (and soul!) needs by eating the things you crave alongside foods that will support your gut to minimize symptoms.
What you need to know is that a) you want to account for how these food cravings alter your digestion and b) that your gut loves routine. Throw off that routine, hello new poops. So, in addition to whatever you’re craving, try to continue to include the foods that helps support a healthy gut, such as anti-inflammatory whole plant foods. We’re talking plenty of fruits, vegetables, whole grains, legumes, nuts and seeds.
Constipation is no fun and can really tank your energy levels so it’s worth taking action. When your menstrual cycle seems to throw off digestion more often than not, it’s worth thinking ahead. I recommend that you create some sort of soft structures that build routine into your day to maintain consistent hydration and fibre intake all cycle long. For example, maybe you grab yourself a new, bigger water bottle so you can keep your hydration up with ease. Or, perhaps you swap your usual sandwich bread for sprouted grain bread to boost fibre intake effortlessly. Or, you commit to eating high fibre beans daily for their soluble fibre.
Magnesium for constipation
Magnesium oxide is used as an osmotic laxative in some countries such as Japan, although it is not generally recognized as an evidence-based option in North America. One 2021 trial suggested that magnesium worked as well as a senna-based laxative. Osmotic laxatives work by drawing water into the bowel, hydrating hard stools making them easier to pass without stimulating contractions. If you don’t have any contraindications for taking magnesium (like medications that alter magnesium levels) this may be a safe and affordable option for occasional relief.
Nausea before your period?
If nausea is an issue for you, brewing strong ginger tea or chewing dried ginger may help alleviate it. Ginger is a prokinetic, meaning that it helps with the movement of the gut and is an evidence-based option for the nausea in pregnancy (which is also linked to progesterone!).
What to eat before your period if you’re constipated
If you track your period poop and know that constipation is often an issue for you pre-period, try creating a simple morning routine in the 3-4 days pre-period to help alleviate sluggish bowels.
- Wake up at a consistent time each day, early enough that you have 15-20 minutes of calm time before you have to get ready to leave.
- Drink 2 cups (500 mL) of water immediately upon rising. It will help with hydration but also help to stimulate the gastrocolic reflex that encourages bowel movement.
- Get your morning tea or coffee going, then go sit on the toilet for just 10 minutes, without your phone. Don’t force a bowel movement, you’re simply trying to signal to your body that now is the right time to go. It’s also great relaxation time (do some deep breathing or something!). Over time, your gut might get into the habit of a morning constitutional.
- If you can, incorporate some psyllium into your breakfast smoothie, oatmeal or some coconut yogurt and granola. Psyllium is a soluble fibre that is low fermentation (low gas!) that helps to regulate digestion, both promoting elimination in constipation and helping to bind up loose stools. Start with 1 teaspoon of psyllium husks if you typically eat a low fibre diet and work up to 1 tablespoon over time.
- Enjoy high fibre foods, but don’t go overboard. Adding a bunch of fibre on top of a constipated gut can make you miserable, especially if you don’t typically eat a lot of fibre. If you’re new to the fibre game, consider just 1 high fibre meal a day to start.
What to eat during your period if you have diarrhea
If period poop looks like loose stools and diarrhea, psyllium is also a good idea – as is hydration to help prevent dehydration. Your gut typically reabsorbs a lot of water from the stools so when stools are more liquid, that means your body will need extra water to account for losses.
During your period, you may want to cut down your coffee intake, as coffee may stimulate the bowels and make loose stools worse. Try matcha tea or brewed black tea (without milk) instead; the tannins in tea may also help with diarrhea.
Enteric-coated peppermint oil is an anti-spasmodic (helps to relieve intestinal spasms) so it may help reduce cramping and bloating. It is an evidence-based therapy for IBS but has not been tested in menstruation-associated symptoms to my knowledge. Not all peppermint oil capsules are vegan – so check the label – and peppermint oil capsules are NOT the same as essential oils. Do not take essential oils internally.
For a day or two, if the diarrhea or loose stools are significant, you may also find it helpful to eat a bit less fibre overall, with a focus on foods that are easy to digest and soothing to the gut. Great examples of this are bananas, oatmeal, tofu, soft roasted vegetables, soups or mild curries. In addition, eating more soluble fibre helps form a soothing gel in the gut that may improve elimination.
Best Sources of Soluble Fibre
- psyllium husk
- ground flax
- chia seeds
- Brussels sprouts
- beans such as black beans and kidney beans (eat in small 1/4 – 1/3 cup servings if you don’t eat them regularly)
The Scoop on Period Poop
It’s clear that our menstrual cycles are messing with our poop. Unfortunately, there is SO much more we have to learn about how sex hormones impact digestive symptoms in the healthy population. The vast majority of research I found was in the inflammatory bowel disease population and you can’t really apply that to those without it. I was disappointed to find very few clinical trials examining this relationship. If you have research to share, I would love to see it so I can continue to improve this post.