Everyone’s bowel movements are different. Some people may go several times a day. Others may only go a few times a week or less.

What’s important is that your bowel movements come out soft and painlessly.

You may have the occasional watery diarrhea or hard stools that seem to take forever to pass. Diarrhea and constipation are both normal occasionally.

But it’s not typical to have both happen regularly.

Let’s get into:

  • what can cause constipation after diarrhea
  • how you can treat it at home
  • when you may need to seek medical help to reduce your symptoms or address the underlying cause

Here are some common causes of constipation after diarrhea and how they relate to what’s happening in your body.

Stomach flu

Stomach flu, or viral gastroenteritis, is a temporary viral infection of your GI tract that results in the inflammation of tissues inside your stomach and your intestines.

Diarrhea is one of the most common and well-known symptoms of stomach flu around the world.

This happens because the bowels swell up and can’t absorb water as easily. This causes liquid to pass through your bowels unused and results in diarrhea.

Swelling caused by infections also causes your intestines to push out much of the existing waste matter that’s already in your intestines.

But you can also experience constipation after a bout of stomach flu because of the lingering muscle inflammation.

This is because the muscles lose some of their strength and elasticity while they’re swollen from infectious material. This causes waste to back up in your intestines and become impacted.

You may continue to experience alternating bouts of diarrhea from unabsorbed water and impacted stool anywhere from a few days to a few weeks.

It will go away once the infection is treated and the inflammation fully heals.

Pregnancy

It’s normal to have constipation and diarrhea when you’re pregnant. There are a few key reasons for this:

  • Changes in your diet is especially common if you start eating new foods that your body’s not used to digesting. This could upset your stomach and cause diarrhea, or slow your intestinal muscles down and cause constipation.
  • Food sensitivities or allergies to new foods can result in both constipation and diarrhea. This occurs as your immune system responds to substances in food or liquids that it now identifies as harmful foreign allergens.
  • Prenatal vitamins can also cause changes in your bowel movements, resulting in diarrhea or constipation.
  • Changes in hormones can affect the speed and movements of your GI tract, as well as many of the substances in your body that are involved in digestion.
  • Pressure put on your bowels from your growing fetus can cause stool to impact as it squeezes through the narrower spaces in your colon, resulting in constipation.

Inflammatory Bowel Disease (IBD)

Both constipation and diarrhea are common symptoms of inflammatory bowel diseases (IBD) like Crohn’s disease and ulcerative colitis.

Each type of IBD affects a different part of the GI tract. Crohn’s can happen anywhere in your GI tract, but it’s most common near the end of your small intestine, where it transitions into the large intestine (colon).

Ulcerative colitis happens only in the colon.

It’s not clear what causes IBD, but its symptoms have been studied closely.

A 2010 study suggests that tissues in the intestines of people with IBD don’t properly transport sodium and fluids.

They also don’t properly absorb bile acid produced by the liver during digestion. Unabsorbed fluids and bile can result in watery diarrhea.

And some IBD conditions are autoimmune disorders. This means that your body’s own immune system is mistakenly attacking your intestinal tissue.

This can cause inflammation or changes in GI muscle movements that can slow down the transit of stool through your colon. This slowdown can then result in stool building up and becoming impacted.

Irritable Bowel Syndrome (IBS)

Not to be confused with IBD, irritable bowel syndrome (IBS) is a term for irregular bowel movements that result from outside influence, such as:

  • your diet
  • stress
  • changes in your gut bacteria

Diarrhea and constipation are both common IBS symptoms, along with

  • pain
  • cramps
  • fatigue

But unlike IBD, IBS isn’t necessarily caused by an autoimmune condition or genetic issues that affect your gut.

IBS is usually diagnosed as one of three categories based on how much you have diarrhea or constipation during an irregular bowel episode:

  • IBS-C (Constipation): over 25 percent of your bowel movements are lumpy and hard
  • IBS-D (Diarrhea): over 25 percent of your bowel movevements are watery and loose
  • IBS-M (Mixed): over 25 percent of your bowel movements are lumpy and hard, and an additional 25 percent are watery and loose

IBS-M often results in alternating episodes of constipation and diarrhea. This is sometimes known as the constipation/diarrhea cycle.

Here are some common clinical treatments for the conditions or causes of constipation after diarrhea discussed above.

Stomach flu

  • Over-the-counter oral rehydration solutions (OHS) like Pedialyte can help you maintain your fluid and electrolyte balance.
  • Probiotics can help restore healthy gut bacteria affected by infection.

IBD

IBS

  • antidepressants, such as fluoxetine (Prozac) or citalopram (Celexa), to reduce anxiety and stress
  • antidiarrheal medications, such as loperamide and diphenoxylate, to slow down muscle contractions in your GI tract
  • antispasmodics, such as belladonna alkaloids and peppermint oil, to reduce cramping
  • bile acid sequestrants, such as cholestyramine and colesevelam, if antidiarrheal medication doesn’t work well
  • fiber supplements to bulk up stool and make it easier to poop
  • laxatives, such as lactulose or polyethylene glycol 3350 (MiraLAX), for constipation or stool softening

Here are some home remedies you can try to help ease the symptoms of constipation after diarrhea or to help avoid it altogether:

  • Use a heat pack or heating pad for about 15 minutes at a time on your stomach to make cramps feel better.
  • Drink an adequate amount of water daily to keep your fluid levels balanced.
  • Do some light to moderate exercise regularly to keep your bowels moving.
  • Boil down brown rice and drink the water to restore electrolytes lost from diarrhea.
  • Eat ginger, or drink ginger ale or ginger tea to calm down your stomach.
  • Eat mint or drink mint tea to make yourself feel less nauseous.
  • Eat dairy products like unflavored kefir or yogurtonce your most severe symptoms have passed to help regain a healthy balance of gut bacteria.
  • Eat more fiber to help move food more easily along your GI tract.
  • Avoid gluten if it causes you to have irregular bowel movements.
  • Try following the low-FODMAP diet to help reduce episodes of irregular bowel movements. This involves reducing foods like dairy, legumes, and fruits and vegetables high in simple sugars called fructose.
  • Take probiotics to help promote healthy gut bacteria.
  • Reduce your stress and anxiety, which can both trigger diarrhea and constipation.
  • Limit smoking if you smoke and limit alcohol consumption, which can both cause constipation and diarrhea as well as trigger symptoms of IBD or IBS.

Having diarrhea for 2 to 3 days or more can dehydrate you. Becoming severely dehydrated can be life-threatening or cause complications, especially if you’re pregnant.

See your healthcare provider if you notice any of the following symptoms of dehydration:

Severe constipation can also cause complications if you don’t have a bowel movement for weeks or longer.

See your healthcare provider if you notice any symptoms from constipation:

  • swollen veins around your anus (hemorrhoids) from straining
  • torn anus skin (anal fissure) from a large or hard stool
  • constant feeling that you have to poop even when nothing comes out
  • stool that can’t be expelled
  • part of your intestine sticking out of your anus (rectal prolapse) from straining

Constipation after diarrhea isn’t common, but it can happen.

See your healthcare provider if it happens regularly, especially if it occurs along with other painful or uncomfortable symptoms.