Loose stools are unusually watery bowel movements. Causes may include gastrointestinal infections, ulcerative colitis, and thyroid problems, among others.

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Loose stools often occur after eating, but they may also happen at other points in the day. They are distinguished from normal stools by:

  • being softer
  • being watery, mushy, or shapeless
  • sometimes having a strong, foul odor

Diarrhea is when a person experiences three or more loose and watery stools throughout the day.

That said, some people may experience loose stools without having diarrhea.

This article will outline the potential causes and some home remedies for loose stools.

It is common to occasionally have loose stools after eating. These are typically caused by dietary trends, infections, or food poisoning.

Some people may also have acute diarrhea, which is when they experience loose and wet stools for up to 14 days.

Dietary trends

Certain foods, drinks, and supplements could increase the likelihood of loose stools or diarrhea occurring.

This could happen if the small intestine cannot properly digest large amounts of certain sugars efficiently.

For example, sugar alcohols which are found in many fruits, vegetables, and artificial flavorings may have a laxative effect. Poor sugar digestion could cause an increase in pressure and water in the colon.

Diets high in lactose, a sugar found in milk-based products, may also cause loose stools. When lactose is malabsorbed by the small intestine, it may be fermented in the gut microbiota and cause diarrhea, abdominal pain, and bloating.

Approximately 36% of people in the United States have lactose malabsorption.

Loose stools may also be caused by diets high in:

Infections or food poisoning

Viruses, bacteria, or parasites may cause inflammation in the stomach and intestines, which can lead to loose stools.

Infections from viruses are the most common cause of loose stools and acute diarrhea.

For example, norovirus is responsible for nearly 58% of foodborne illnesses in the United States and affects 19-21 million people. Rotavirus and viral gastroenteritis are two common viruses that may also cause symptoms, such as:

Bacteria are also responsible for foodborne illnesses, such as:

Some people may experience chronic bouts of loose and wet stools, known as chronic diarrhea. This lasts longer than four weeks, is typically caused by an underlying health condition, and may require treatment.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic condition affecting the digestive system. Between 10-15% of people in the United States have IBS, and it tends to affect females more than males.

Loose stools and diarrhea are common symptoms of IBS.

Other symptoms may include:

Ulcerative colitis

Ulcerative colitis (UC) is a chronic condition that causes inflammation and ulcers in the colon.

It is estimated that between 600,000-900,000 people in the United States have UC.

Symptoms of UC include:

Crohn’s disease

Crohn’s disease is a long-term condition that affects nearly 500,000 people in the United States.

This condition happens when the lining of the digestive system becomes inflamed.

It may cause diarrhea and loose stools, as well as:

  • abdominal pain
  • blood in fecal matter
  • appetite and weight loss
  • fatigue

Celiac disease

Celiac disease is an autoimmune condition that causes inflammation of the small intestine. It is triggered by eating foods with gluten, which is naturally found in wheat, barley, and rye.

This condition affects nearly 2 million people in the United States.

Symptoms of celiac disease include:

  • diarrhea and loose stools
  • abdominal pain, bloating, or gas
  • indigestion
  • skin irritation
  • fatigue
  • weight loss

Bile acid malabsorption

Several liver and gallbladder disorders may impair the proper function of bile, which helps properly break down fats in the intestines. This may occur in people with gallstones or liver cirrhosis.

Bile acid malabsorption may cause diarrhea or loose stools.

Overactive thyroid (hyperthyroidism)

An overactive thyroid is when the thyroid gland produces too many hormones, interfering with its normal function.

This may cause loose stools and diarrhea, as well as:

Chronic pancreatitis

Chronic pancreatitis is an inflammatory condition that affects the pancreas and could impair the proper breakdown of fats, starches, and proteins.

Approximately 40-70% of diagnoses are caused by chronic alcohol consumption.

Symptoms of chronic pancreatitis may include:

  • loose stools and diarrhea
  • abdominal pain
  • nausea
  • vomiting

Cystic fibrosis

Cystic fibrosis is a long-term condition where mucus builds up in the lungs and digestive system. This may interfere with digestion and cause symptoms like:

Dumping syndrome (rapid gastric emptying)

Dumping syndrome is a condition where food moves from the stomach to the bowel too quickly. It often occurs after weight-loss surgery and may cause symptoms like:

Infrequent cases of loose stools do not typically require medical treatment. However, multiple cases of loose stools may cause dehydration and malnutrition.

Some home remedies may help loose stools caused by dietary trends, infections, or food poisoning return to normal after a few days. These may include:

  • making dietary changes, such as trying the BRAT diet
  • taking anti-diarrhea medication, such as Imodium
  • staying hydrated
  • consuming probiotics

Loose stools that do not improve after 48 hours should be given immediate medical attention. This may be a sign of a more serious medical condition and may worsen without treatment.

Treatment for chronic conditions may include prescription medications, antibiotics, or hospital treatment. In some cases, there are no available cures for the underlying condition, but symptoms may be managed.

People with chronic conditions should work with a doctor to help them manage their symptoms and prevent complications.

What does it mean if your stool is loose?

Loose and wet stools are characterized by their appearance, texture, and sometimes smell.

Compared to a normal stool, loose stools may be:

  • softer
  • watery, mushy, or shapeless
  • more foul-smelling

What is the most common cause of loose stools?

Infrequent loose and wet stools are most commonly caused by consuming certain foods and drinks, or viruses, bacteria, and parasites.

When should I be concerned about loose stools?

Loose and wet stools may occasionally happen after eating certain foods.

However, it’s important to get medical attention if a person experiences diarrhea and the following symptoms for more than 48 hours:

  • bloody diarrhea
  • abdominal pain
  • illness

In most cases, infrequent loose stools will subside within a few days without treatment or with home remedies.

It is important to distinguish between loose stools that occur infrequently and those that are chronic. Experiencing loose stools that persist for over 48 hours may indicate a more serious underlying condition that will require immediate medical attention.