Do Women Poop More Than Men? The Biology Explained

Women do not poop more than men. The research consistently points in the opposite direction: women tend to have slower colonic transit, less frequent bowel movements, and a greater tendency toward constipation. That said, the picture is more nuanced than a simple “men go more.” Hormonal cycles create temporary surges in frequency, certain life stages reshape the gut’s behavior entirely, and the gap between the sexes narrows or disappears depending on which population you study and how you define “normal.” The biology behind all of this involves everything from colon length to smooth-muscle chemistry to the pelvic floor.

What Frequency Studies Actually Show

One of the largest early surveys of bowel habits in a general population found that about a third of women defecated less often than once a day, and stools at the constipated end of the scale were passed more often by women than by men. Among women of childbearing age, the pattern shifted even further toward constipation and irregularity compared with older women in the same study.¹ A separate Swedish population study, however, found no difference in stool frequency between men and women once people with irritable bowel syndrome were excluded. The sex gap in symptoms like bloating, pain, and constipation disappeared once IBS was taken out of the equation.²

So the truth lands somewhere in the middle: among healthy people without a functional gut disorder, men and women may poop at roughly the same rate. But women are more likely to have conditions that drag frequency down, and the baseline physiology leans toward slower movement through the colon. The idea that women poop more often is not supported by any major study.

Slower Transit Through the Colon

One of the most consistent findings in gastrointestinal research is that food moves through the colon more slowly in women. A study measuring regional gut transit found that colonic transit was significantly faster in men, along with faster post-meal gastric emptying.³ This difference holds up even after adjusting for total calorie intake, diet, body weight, and height. The sex gap is most pronounced in the far end of the colon, the transverse and descending segments, where women show notably longer transit times.⁴

In a controlled feeding study where men and women ate identical amounts of dietary fiber, men still had faster transit and heavier daily stools. Women also appeared to digest more of the fiber, squeezing more out of it before what remained was expelled. Even when you equalize the diet, the gut itself behaves differently.⁵ Another study of healthy adults in the UK measured a median whole-gut transit time of about 55 hours in men versus 72 hours in women, and about 17 percent of women but only 1 percent of men passed less than 50 grams of stool per day.⁶

Why Hormones Slow Things Down

The main culprit behind slower female transit is progesterone, the hormone that rises during the second half of the menstrual cycle and surges during pregnancy. Progesterone relaxes smooth muscle, including the muscle that lines the intestinal wall and propels food along. It does this partly by boosting nitric oxide, a chemical that tells smooth muscle cells to relax, and partly by interfering with the signaling pathways that trigger contraction.⁷ At a cellular level, progesterone reduces calcium currents in intestinal smooth muscle cells, and calcium is what these cells need to contract.⁸

Estrogen plays a supporting role. Research on gastric smooth muscle cells shows that estrogen also increases nitric oxide levels and inhibits the contraction triggered by normal digestive signals.⁹ The combination of both hormones creates a gut environment that favors slower transit and more water reabsorption from stool, which is why constipation tracks so closely with reproductive hormones.

The Menstrual Cycle Exception

There is one recurring window when many women do notice increased bowel activity, and that is the first day or two of menstruation. A prospective study of healthy women found that stool frequency, stool looseness, abdominal pain, diarrhea, and indigestion all peaked on day one of bleeding. Diarrhea symptoms on that first day were significantly higher than on all other days of the cycle.¹⁰

The mechanism is prostaglandins, chemicals released by the uterine lining to trigger contractions that shed the endometrium. Prostaglandins do not stay neatly confined to the uterus. They spill into surrounding tissues, and when they reach the intestines, they stimulate the same kind of smooth-muscle contractions there. The result is looser, more frequent stools right around menstruation. This is the source of the common experience sometimes called “period poops.” It is real, it is well documented, and it represents a temporary reversal of the usual pattern. But it lasts a day or two out of roughly 28, so it does not change the overall frequency picture.

An earlier study looking at gastrointestinal symptoms across the full menstrual cycle in a small group of women, however, found no significant differences in stool consistency or frequency between cycle phases, suggesting the effect may vary between individuals.¹¹ Not every woman experiences dramatic menstrual bowel changes, but enough do that it is one of the most common bowel-related complaints in gynecological practice.

Anatomy Makes a Difference Too

Hormones get most of the attention, but the physical layout of the colon also differs between sexes. A CT colonography study found that the female colon was significantly longer than the male colon, averaging about 154 centimeters versus 147 centimeters. The difference was most pronounced in the proximal colon, the first stretch after the small intestine.¹² An earlier colonoscopy-based study found a similar gap, with women having a median total colonic length of 155 centimeters compared to 145 centimeters in men. The biggest difference was in the transverse colon, the segment that crosses the upper abdomen, which was about 8 centimeters longer in women. The transverse colon also dropped down into the true pelvis far more often in women than in men.¹³

A longer colon means more surface area for water absorption and a longer path for stool to travel, both of which contribute to harder, drier stools and slower passage. This is part of the reason colonoscopy tends to be technically harder and more uncomfortable in women: the scope has more distance to cover and more curves to navigate.

Stool Form and Consistency

Even when frequency is similar, what comes out is not identical. A Japanese study found that the proportion of hard stools was higher in women, while the proportion of loose stools was higher in men.¹⁴ This makes sense given the slower transit time: the longer stool sits in the colon, the more water gets pulled out, and the firmer it becomes. A community-based study using stool form as a proxy for transit speed found that men had about 40 percent lower odds of slow transit compared with women.¹⁵

An Indian cross-sectional study added an interesting wrinkle: men actually reported both more hard stools and more loose stools than women, while women clustered around the middle of the stool form scale.¹⁶ This could reflect dietary or cultural factors specific to that population. The general trend across most studies, though, is that women lean toward the firmer end of the spectrum.

Pregnancy Pushes the Pattern Further

If progesterone slows the gut during a normal cycle, pregnancy takes it to another level. Constipation is one of the most common gastrointestinal complaints during pregnancy, driven by the combination of soaring progesterone, a growing uterus physically compressing the colon, and changes in physical activity and iron supplementation.¹⁵ A review of gastrointestinal motility during pregnancy found reduced transit rates in both the small bowel and colon, with progesterone identified as the primary driver and estrogen acting as a primer that amplifies progesterone’s effects on smooth muscle.¹⁷ Women who already struggled with constipation before conception often find it worsens during pregnancy.

Menopause and the Hormonal Shift

You might expect constipation to ease after menopause, when progesterone and estrogen levels drop. The reality is more complicated. A study comparing premenopausal and postmenopausal women found that about 38 percent of postmenopausal women reported altered bowel function, compared with 14 percent of premenopausal women. Despite this, the two groups did not differ in the prevalence of abdominal pain, diarrhea, or constipation specifically suggestive of IBS. Complaints like excessive gas and heartburn were also more common after menopause.¹⁸

The Seattle Midlife Women’s Health Study tracked women through the menopause transition and found that no specific stage of menopause predicted constipation severity, and none of the reproductive hormones measured were significantly associated with constipation. What did predict worse constipation was stress, specifically tension and anxiety.¹⁹ So the hormonal explanation for constipation, which works well during reproductive years, does not map cleanly onto what happens at menopause. Aging itself, changes in physical activity, pelvic floor weakening, and stress may matter more at that stage.

IBS and the Symptom Gap Between Sexes

Irritable bowel syndrome is more common in women, and the predominant subtype in women is IBS with constipation, while men with IBS are more likely to report diarrhea.²⁰ This means that even in the population most likely to have altered bowel habits, women are still skewing toward fewer and harder stools rather than more frequent ones. Women with IBS also tend to report more severe symptoms overall, along with higher rates of fatigue, anxiety, and depression compared with men who have IBS.²¹

This is one reason the Swedish population study found that the sex gap in bowel symptoms disappeared once IBS was excluded. The disorder itself accounts for a large chunk of the apparent difference between men and women in everyday bowel complaints. Remove it, and the remaining population looks more similar than different.

The Pelvic Floor Factor

The pelvic floor muscles matter for defecation because they support the rectum and help control the release of stool. Women generally have weaker voluntary contraction strength in these muscles compared with men, and they more frequently show dysfunctional endurance during sustained contraction.²² Defecatory disorders, where the pelvic floor muscles fail to coordinate properly during a bowel movement, are more common in women and are a well-recognized cause of constipation.²¹ Pregnancy, vaginal delivery, and aging can all damage or weaken the pelvic floor, compounding the issue over time.

Gut Microbiome Differences

The bacteria living in the gut also vary between sexes, though the research here is still developing and results are inconsistent across studies.²³ A 2025 systematic review found that women generally have higher levels of certain bacterial groups while men tend to have more of others. The review concluded that sex is a contributing but not dominant variable shaping the microbiome, with hormonal fluctuations, body composition, and lifestyle all playing a role.²⁴ The distribution of gut bacteria also shifts with age, puberty, pregnancy, and menopause, all of which affect women differently than men.²⁵

Whether these microbial differences directly cause the bowel-habit differences between sexes, or whether they are a consequence of the hormonal and transit-time differences already described, remains an open question. The microbiome field moves fast, but its findings on sex-specific bowel habits are not yet firm enough to draw strong practical conclusions from.

Medications and GI Side Effects

One often-overlooked factor is that women experience gastrointestinal side effects from medications at higher rates. A large retrospective study of opioid side effects found that women were about three times more likely than men to report gastrointestinal reactions.²⁶ This extends beyond opioids; many drug classes are dosed based on body weight or standard adult dosing that was historically calibrated on male subjects. The result is that medication-related constipation or diarrhea may hit women harder, not because their gut is inherently different in that regard, but because the drug exposure ends up being proportionally greater.

The Psychosocial Layer

Biology is not the only thing at play. Bathroom behavior is shaped by social comfort, and that comfort differs by sex. Research on “shy bowel,” the anxiety-driven avoidance of using public or shared restrooms for defecation, found that women scored significantly higher on shy-bowel measures than men.²⁷ Holding stool in because of social discomfort does not change the underlying biology, but it can affect day-to-day frequency and contribute to constipation over time. It also means that self-reported bowel frequency may underrepresent actual urges in women more than in men, muddying the survey data.

Female athletes offer another angle. A review of gastrointestinal issues in female athletes found that women generally reported more GI symptoms at rest, particularly during menstruation, but not during exercise itself.²⁸ Exercise is well known to speed up gut transit, so high physical activity levels may partially offset the hormonal slowdown in active women. But the menstrual-cycle symptoms persist regardless of fitness level, reinforcing that the hormonal driver operates independently of activity.