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Foul smelling poops can signal a medical condition

Foul-smelling stool has a particularly bad odor. Often, this is due to the foods that people eat. In some cases, however, foul-smelling stool can indicate an underlying medical condition. These can be serious medical matters.

Foul Smelling Poops

Below are eight common causes of foul-smelling stools.

Celiac Disease

According to the American Gastroenterological Association (AGA), people with celiac disease experience an immune reaction to eating gluten, which is a protein present in wheat, barley, and rye.

In celiac disease, the immune system overreacts to the presence of gluten and attacks the lining of the small intestine.

Ongoing damage can cause malabsorption, or an inability to absorb adequate nutrients from food. This can lead to further complications.

Common symptoms of celiac disease include:

  • pale, fatty, or foul-smelling stool
  • persistent bloating, gas, or abdominal pain
  • persistent diarrhea or constipation
  • weight loss or gain
  • confusion, tiredness, and fatigue
  • bone or joint pain
  • tingling or numbness in the legs
  • muscle cramps
  • mouth sores
  • a skin rash that itches

Antibiotics and Infections

 People taking antibiotics may experience temporary stomach upset and foul-smelling stool. This is because antibiotics can disrupt the delicate balance of good and bad bacteria within the gut.

Symptoms usually disappear soon after finishing a course of antibiotics, once the good gut bacteria have replenished.

Occasionally, antibiotics can destroy so many of the good intestinal bacteria that the harmful ones multiply out of control, causing infection.

People who experience an overgrowth of harmful intestinal bacteria while taking antibiotics may notice the following symptoms:

  • watery, foul-smelling diarrhea, which may contain pus or blood
  • pain, tenderness, and cramping in the abdomen
  • fever

Lactose Intolerance

 Lactose is a type of sugar present in milk and other dairy products. The human body breaks lactose down, and an enzyme called lactase digests it.

A person who is lactose intolerant does not produce enough lactase to digest lactose.

People who are lactose intolerant may experience the following symptoms after consuming milk products:

  • loose, foul-smelling stool
  • bloating and gas
  • abdominal cramping
  • nausea

Milk Allergy

The American College of Allergy, Asthma & Immunology (ACCAI) explain that having a milk allergy is not the same as having lactose intolerance.

People who have a milk allergy experience an immune reaction to milk and dairy products.

Symptoms of milk allergy include:

  • bloody, foul-smelling stool
  • upset stomach
  • vomiting
  • hives
  • anaphylaxis, a rare but potentially life-threatening allergic reaction

Short Bowel Syndrome

Short bowel syndrome (SBS) is a rare condition that occurs when a portion of the small or large intestine is absent or unable to function.

Because of this, people with SBS often experience malabsorption, which can cause serious complications.

SBS can occur for many reasons. A common cause is the surgical removal of part of the bowel following treatment for inflammatory bowel disease (IBD).

The symptoms of SBS vary among people but may include:

  • pale, greasy, foul-smelling stool
  • severe diarrhea
  • dehydration
  • weight and muscle loss
  • lethargy
  • malnutrition
  • bloating

Ulcerative Colitis

Ulcerative colitis is a chronic type of IBD. In ulcerative colitis, the lining of the colon becomes inflamed and develops ulcers.

Many experts believe that ulcerative colitis occurs when the immune system mistakes “friendly” intestinal bacteria for harmful bacteria.

In response, it sends white blood cells to the intestines to help fight infection. For some reason, this response fails to switch off, and white blood cells continue to flood the large intestine, causing chronic inflammation.

People with ulcerative colitis may develop a range of symptoms, including:

  • foul-smelling stool containing blood or mucus
  • diarrhea
  • constipation
  • bowel incontinence
  • abdominal cramps

Crohn’s Disease

Crohn’s disease is another type of IBD. It can affect any part of the gastrointestinal (GI) tract. Common symptoms include:

  • an urgent need to empty the bowel
  • persistent and foul-smelling diarrhea
  • constipation
  • rectal bleeding
  • a feeling of incomplete bowel-emptying
  • abdominal cramps and pain
  • fever and night sweats
  • fatigue
  • loss of appetite
  • weight loss

Chronic Pancreatitis

Chronic pancreatitis is persistent inflammation of the pancreas that gets worse over time. Chronic pancreatitis causes irreparable damage, which affects a person’s ability to digest food and make pancreatic hormones.

Symptoms may include:

  • oily, fatty, foul-smelling stool
  • nausea
  • vomiting
  • pain in the upper abdomen and back, which worsens when eating or drinking
  • pale or clay-colored stool
  • malnutrition and weight loss


Any of these serious conditions can cause really bad smelling bowel movements, however that is only one indicator. If you suspect any of these medical problems, see your doctor at once.


(Source: Medical News Today,