Bowel Movement Changes in Pregnancy

Pregnancy brings about many changes in a woman’s body and in the functioning of its various systems, including the gastrointestinal system. Changes in bowel movement, such as constipation is fairly common in pregnant women but occasionally diarrhea can occur for no known reason.

Pregnant women may have a variation of their normal bowel movement, alternating between constipation and diarrhea. In most cases, alteration in diet and certain lifestyle changes can restore normal bowel movements and definitive treatment becomes necessary only in case of specific causes of such problems.

What is Normal Bowel Movement?

It is difficult to define normal bowel movement. Bowel movements can vary from person to person and what is normal in one person may not be considered so in another. A lot of people do not have regular motions every day. A person may normally have one to three bowel movements in a day, or she may have motions every other day without feeling any discomfort.

Pregnancy Bowel Habits

A woman otherwise having normal bowel habits may suffer from bouts of constipation or diarrhea during pregnancy. An alteration in pregnancy hormones at different stages of pregnancy can bring about this change.


Broadly speaking, constipation may be defined as having three or less bowel movements in a week, with passage of hard dry stool. A person may often have to strain while trying to pass stool. This can cause or aggravate anal fissure or hemorrhoids, leading to pain during defecation or fresh blood in stool (hematochezia).

Causes of Pregnancy Constipation

  • With changing hormone levels in the body during pregnancy there is a change in bowel movements as well. This is most commonly manifested as constipation. The pregnancy hormone progesterone by its action of relaxing all smooth muscles also helps to relax the intestinal muscles, thus slowing peristalsis and affecting small intestinal motility as well as colonic motility. This results in sluggish bowel movements and constipation.
  • Due to slow bowel movements there is increased absorption of water in the intestines.
  • Mechanical pressure by the growing uterus on the intestines and rectum.
  • Low fiber content in the diet.
  • Low water intake.
  • Lack of physical activity.
  • Medicines taken during pregnancy such as iron supplements and calcium, or antacids containing aluminum or calcium.
  • Avoiding passing stool because of anticipated pain in case of hemorrhoids or anal fissures.
  • Specific conditions such as irritable bowel syndrome (IBS).

Treatment of Pregnancy Constipation

  • Drinking adequate fluids.
  • Including enough fruits, vegetables, and other high fiber foods in the diet.
  • Restricting caffeinated drinks such as coffee, tea, and some sodas.
  • Not trying to hold in bowel movements.
  • Regular exercise, such as walking or swimming.
  • Laxatives or stool softeners should only be taken when prescribed by a doctor.
  • Changing the iron supplement being used for a different one with a lower iron content.
  • Herbal remedies should not be taken without consulting a doctor since these may be harmful if taken during pregnancy.
  • Treatment of the specific cause of constipation.


Diarrhea is defined as frequent bowel movements, more than three times a day, with passage of loose, watery, or unformed stool. Although constipation is more common during pregnancy, many women suffer from diarrhea too, due to a number of causes.

Mild diarrhea in pregnancy usually resolves on its own and should not be a cause for concern.

However, diarrhea in a pregnant woman should not be ignored, especially when it is continuing for more than two days or if it is accompanied by nausea and vomiting, fever, abdominal pain, or signs of dehydration. It is important to guard against dehydration, which is one of the most common and serious complications of persistent diarrhea. The signs of dehydration may include dryness of mouth and lips, dry skin, excessive thirst, loss of skin turgor, and decreased urine output.

Severe diarrhea or diarrhea persisting beyond two days may affect the well-being of both mother and baby.

Causes of Pregnancy Diarrhea

  • Infectious gastroenteritis and food poisoning
    • Viral infection due to rotavirus, norovirus, or adenovirus is the most common cause of diarrhea. The symptoms are usually mild and most cases recover on their own without any treatment.
    • Bacterial infections – usually due to Campylobacter, Salmonella, Shigella, or Escherichia coli (E. coli). These result in more serious types of diarrhea or food poisoning, usually caused by contaminated food or drinks.
    • Parasitic infections by Giardia lamblia, Entameba histolytica, and Cryptosporidium are also caused by contaminated food and water.
  • Dietary changes during pregnancy. Many pregnant women often consume larger amounts of fruits and vegetables than usual for the health benefits.
  • Hormonal changes in pregnancy.
  • Reaction to medicines, especially antibiotics and antacids.
  • Laxative abuse in an attempt to relieve constipation in pregnancy.
  • Diarrhea in late pregnancy may be an indication of impending labor.
  • Food sensitivities during pregnancy.
  • Unusual food cravings in pregnancy. Pica (craving for and consuming non-food items such as mud, chalk, sand, starch and so on) can be a cause of pregnancy diarrhea.
  • Food intolerances, most commonly lactose intolerance.
  • Symptoms of inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis often get exacerbated during pregnancy.
  • Irritable bowel syndrome (IBS).

Treatment of Pregnancy Diarrhea

  • Mild diarrhea usually does not need any treatment since it subsides on its own. Determining the cause of diarrhea and treating accordingly is important especially for infectious causes.
  • Bland diet is usually recommended. BRAT diet (bananas, soft rice, applesauce and dry toast) may be given.
  • Prevention of dehydration is important. Correcting dehydration by means of oral fluids. Oral rehydration solutions (ORS) are often necessary to ensure adequate water and electrolyte intake.
  • Avoiding food or medicines that cause diarrhea.
  • Avoiding dairy products and caffeine.
  • In case of severe diarrhea with vomiting, intravenous fluids may become necessary.
  • Medicines to stop diarrhea should be taken only after consulting with the doctor since many drugs can cause adverse effects if taken during pregnancy. Loperamide is considered safe to use, even during the first trimester. Anti-diarrheal medication containing diphenoxylate with atropine, and bismuth subsalicylate should not be used in pregnancy.

Related Articles

  1. Constipation during Pregnancy
  2. Diarrhea in Pregnancy

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