Why? Differences in Abdominal Symptoms Between Men and Women

Are you suffering from abdominal discomfort?

As a gastroenterologist, I receive many consultations, especially regarding bowel movements.

Generally, diarrhea is more common in men, while constipation is frequently seen in women.

Why do abdominal symptoms differ between men and women?

The background to this may involve differences in how the intestines react between genders, which is becoming clearer through recent research.

IBS symptoms differ by gender: Men tend to have diarrhea-predominant, women tend to have constipation-predominant

Irritable Bowel Syndrome (IBS) is a condition characterized by chronic bowel abnormalities such as constipation or diarrhea, accompanied by abdominal pain or discomfort.

It is known that even with the same IBS, there are differences in symptoms between men and women.

Generally, women tend to have constipation-predominant IBS, while men tend to have diarrhea-predominant IBS.

Even among undiagnosed potential IBS patients, men seem to suffer more from diarrhea than constipation.

Do you see this trend around you as well?

Why exactly is this?

Recent research is beginning to shed light on part of the cause.

Experiments using mice revealed that when stress stimuli are applied to the large intestine, the components of neurotransmitters sent to the brain differ between males and females.

Specifically, in males, substances that promote peristalsis in the large intestine are secreted more, whereas in females, substances that inhibit peristalsis are secreted more.

In other words, when stress is applied, the intestines start moving in males, while movement weakens in females.

This difference is considered one of the reasons why diarrhea-predominant IBS is more common in men and constipation-predominant IBS is more common in women.

Is diarrhea better than constipation? Risks of diarrhea-predominant IBS

Some people may think that diarrhea is better than constipation because they are not constipated.

However, diarrhea should never be taken lightly.

If diarrhea persists, it may become impossible to sufficiently absorb nutrients necessary for the human body or useful components produced by intestinal bacteria.

In other words, in some cases, the intestinal environment may be worse than that of a person with constipation.

It is said that loose stools are easily affected by stress and irregular lifestyles.

In particular, for modern people living in a stress-filled society, diarrhea can be considered a familiar problem.

If diarrhea persists, it is important not to dismiss it as merely temporary, but to consider reviewing your lifestyle habits and consulting a medical institution.

Causes of diarrhea and constipation: stress, lifestyle habits, and aging

The cause of IBS is not yet clearly understood.

While there are many possibilities, the main ones include stress, lack of exercise, lack of dietary fiber, and excessive alcohol consumption.

These factors can have a negative impact on intestinal motility and the intestinal environment, potentially causing diarrhea and constipation.

Also, as we age, intestinal movement (colonic peristalsis) decreases, increasing the risk of constipation.

Once men reach the age of 50, the prevalence of constipation increases, and constipation is by no means a problem exclusive to women.

Men should also be careful! Colorectal cancer risk and the importance of regular checkups

The figure above is data from the National Cancer Center.
For both men and women, the risk of colorectal cancer increases with age.

In Japan, colorectal cancer accounts for 15.6% of all cancer cases (men: 15.8%, women: 15.6%), making it the cancer with the highest combined total for both men and women.

Even after adjusting for the effects of age, both the incidence and mortality rates of colorectal cancer in Japan remain at a high international level.

Furthermore, even in men, constipation increases with age due to factors such as declining intestinal function.

Chronic constipation is considered a potential risk factor for colorectal cancer.

This is because constipation can cause harmful substances in the intestines to stagnate, remaining in contact with the intestinal mucosa for an extended period, which may promote carcinogenesis.

However, this is merely a possibility, and it has not been definitively established that "constipation" is a direct risk factor for colorectal cancer.

For those aged 35 and older, it is recommended to undergo regular health checkups that include stool tests.

Particular caution is advised for those who have blood relatives with colorectal cancer.

If you experience persistent bowel irregularities such as diarrhea or constipation, or if symptoms like abdominal pain or discomfort continue, you should visit a medical institution promptly to receive an appropriate diagnosis and treatment.

Please also make time to improve your intestinal environment and lifestyle, and to pay attention to your own body.