Menstrual Diarrhea (with Monthly Periods) Causes and Remedies

Diarrhea can arise for may different reasons. Often it is due to infections. However, when the exact cause of diarrhea cannot be conclusively identified yet it tends to arise with certain other conditions or symptoms then it may be correlated. Diarrhea that occurs during menstruation (monthly periods in females) may be linked provided that other more obvious causes cannot be found. It can cause menstruation to be extremely uncomfortable during a time when most women are contending with other symptoms like period pain along with the menstrual flow.

Read more on watery stool.

Causes of Diarrhea with Periods

The exact cause of diarrhea during menstrual periods is not entirely clear. One of the favored theories is that it is associated with prostaglandins as described below. However, there are a host of different mechanisms that could contribute to menstrual diarrhea which also needs to be considered. Diarrhea should not be immediately associated with menstruation unless the frequent and loose stool tends to recur with successive periods.


Prostaglandins are a chemical that stimulate the uterus to contract. This is necessary in menstruation for the uterus to expel the endometrium (inner uterus lining) that sloughs off as part of the normal menstrual cycle when pregnancy does not occur. However, it appears that these substances may also stimulate other smooth muscles (muscles in organs that are not under voluntary control).

The wall of the digestive tract is laden with tiny smooth muscles that contract and relax to push along food and wastes. This process is constantly occurring and is known as peristalsis. Under the influence of prostaglandins, peristalsis in the colon may speed up. As a result the faster bowel motility may contribute to diarrhea. This is believed to be the main reason why diarrhea may occur with the monthly periods.


The prostglandins are also believed to be a major factor in period pain. Along with other factors, many women experience periods pain which can be more severe in some. The effects of pain on the nervous system could also be a contributor to increased activity of the nerves that control the tiny muscles in the bowel wall. However, the opposite can occur in that constipation may arise, especially when certain painkillers are used to control severe period pain.

Premenstrual Syndrome

Premenstrual syndrome (PMS) is a cyclic presentation of various symptoms that appear to be due to the changes of the female hormones during the menstrual cycle. InĀ  some cases it can be severe and debilitating. Apart from the mood swings, fatigue and food cravings, there may also be other symptoms like disruptions in bowel habit. Therefore some women who tend to suffer with premenstrual syndrome (PMS) are more likely to experience diarrhea.


Psychological factors can directly contribute to changes in bowel habit. Sometimes a pre-existing mental disorder or psychological stress may be exacerbated during the monthly periods. This can be due to the changes in hormones, premenstrual syndrome or other factors that are a part of menstruation but may have an impact on a person’s mental or emotional state.

Read more on stress diarrhea.

Change in Diet

Dietary changes just before and during menstruation may be the cause of diarrhea. These changes in diet may sometimes be a result of food cravings that arise with premenstrual syndrome (PMS). Furthermore the excessive use of stimulants like caffeine to counteract the fatigue that may arise with PMS can further play a role in causing or worsening diarrhea.

Irritable Bowel Syndrome

The exact cause of irritable bowel syndrome (IBS) is unclear. It appears to be due to disturbances in bowel motility. Some women with IBS may find that the condition aggravates during menstruation. The reason why this may occur is not always clearly understood. Women with IBS-D (irritable bowel syndrome with diarrhea) or IBS-M (mixed irritable bowel syndrome) may therefore find diarrhea worsen during periods.

Pre-existing Bowel Disorders

Some pre-existing bowel disorders where diarrhea is one of the symptoms may be affected by menstruation. Apart from IBS, inflammatory bowel disease (IBD) also appears to be aggravated during periods in some female sufferers. StudiesĀ¹ have found that symptoms like abdominal pain, nausea and diarrhea worsened during menstruction. The symptoms may not only change with menstruation but with other hormonal fluctuations during the menstrual cycle.

Remedies for Menstrual Diarrhea

The approach to diarrhea during menstruation is not significantly different from treating and managing diarrhea due to other non-infectious causes. The diarrhea tends to be acute, meaning that it lasts for just a short period of time and resolves on its own in most cases.

Read more on how to stop diarrhea.


Rehydration is essential during diarrhea of any cause. There can be profuse loss of fluid and electrolytes in the diarrheal stool. Water on its own is not sufficient to restore lost electrolytes. Fluids like sodas and alcohol are not suitable as these beverages can hasten water loss by aggravating diarrhea or increasing fluid out in urine.


Rest is also important to minimize fluid and electrolyte loss. Therefore strenuous physical activity like vigorous exercise should be avoided until the diarrhea resolves If exertion is unvoidable then thorough hydration is importnt to prevent dehydration.

Avoid Stimulants

Stimulants like caffeinated beverages should be avoided. This includes coffee, tea, colas, energy drinks or other beverages that contain caffeine. Not only does caffeine act as a diuretic and increase fluid loss through urine but stimulants may also increase bowel motility which can worsen diarrhea.

Eat Bland Foods

Solid food should not be stopped during diarrhea. A balanced diet is important to prevent nutritional deficiences that is a risk in prolonged diarrhea. Spicy and greasy foods should be avoided as it can worsen diarrhea. Instead small meals of bland foods should be consumed throughout the day along with appropriate rehydration.


Antidiarrheal medication like loperamide should not be the first choice of treatment for diarrhea unless prescribed by a medical professional. Instead diarrhea should be conservatively managed or the underlying cause should be appopriately treated. Fiber and probiotic supplements may assist with helping diarrhea resolve faster.



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