White Fuzzy Coating on Stool: Causes & When to Worry.

Our content is not intended nor recommended as a substitute for medical advice by your doctor. Use for informational purposes only.

What is the nature of the white fuzzy coating on your stool?

Under normal conditions, The mucus cells in the walls of the small intestine and the colon secret small amounts of mucus.

Mucus serves to keep your digestive system lubricated and moist. It also plays a vital role in regulating your bowel movement and immunity (reference).

Often, a healthy individual will not notice mucus in stool. However, it may appear as a white fuzzy coating on your stool under certain circumstances (see the causes below).

To our knowledge, mucus is the only explanation for the white fuzzy coating on your stool. However, you should consult your doctor about the possibility of other causes or diseases.

Possible causes of White fuzzy coating on the stool.

1. Occasional finding in a normal healthy individual.

Mucus is present in small amounts in a normal healthy individual. Healthy mucus is often a transparent or whitish or yellowish semi-transparent jelly-like substance.

It is unnoticeable under normal circumstances. Moreover, there is no need to worry if you feel fine and notice only a little mucus.

The white fuzzy coating on the stool without other symptoms can occur occasionally. However, it is not normal for the mucus to:

  • Occur more often.
  • The amount is large.
  • Be associated with blood.
  • Be associated with other symptoms such as diarrhea, fever, weight loss, or belly pain.

The above condition reflects an ongoing problem inside your digestive system. The list of common diseases and conditions that can cause a white coating (mucus) on your stool is explained below.

2. Infections.

Mucus helps to trap and force bacteria and other harmful microorganisms out of your intestines. Consequently, any infection will lead to a reflex increase in mucus secretion by your small intestine and colon.

Any infection can cause increased mucus and the formation of a white fuzzy coating on your stool.

For Example:

  • Acute viral gastroenteritis (stomach flu).
  • Acute dysentery.
  • Most types of foodborne illnesses (food poisoning).
  • Not only acute infections but also chronic causes of intestinal infections can lead to white mucus coating your stool.


  • Most often, acute infections cause acute onset diarrhea with mucus (loose or watery stool with mucus).
  • Abdominal pain (Belly pain).
  • Nausea or vomiting.
  • Fever and body aches.
  • Sometimes, blood and mucus in the stool (especially with dysentery).
  • Chronic infections, prolonged mucus in stool, diarrhea, and abdominal pain are the most frequent symptoms.

Learn more about the causes of acute and chronic intestinal infections.

3. Irritable Bowel syndrome.

Irritable bowel syndrome is a very common disease. Many people have IBS and don’t know it.

We don’t know the exact cause of IBS. The disease is classified as a (functional gastrointestinal disease). It is due to abnormal (function), not abnormal lesions.

Mucus in stool is very frequent with IBS. Manning criteria are a method of diagnosis of IBS that includes (mucus in stool) as a part of IBS (reference).

Symptoms of IBS.

  • Recurrent abdominal pain (at least one day per week for the past three months).
  • Abdominal pain can either be relieved or triggered by defecation.
  • Diarrhea, constipation, or both (in periods of flare-ups and remissions).
  • Change in your stool form (with the onset of pain, your stool becomes more hard or loose).
  • Distension and bloating.
  • Mucus in the stool (which can appear as a white fuzzy coating in stool).

Learn More about the diagnosis of IBS here.

4. Food intolerances and allergies.

Food intolerances and allergies are other widespread conditions. Some studies estimate that food intolerance can be as high as 20% of the population.

Intolerance occurs when your digestive system becomes unable to digest certain foods.

Accumulation of the undigested and unabsorbed food triggers intolerance symptoms such as:

  • Distension and bloating.
  • Diarrhea.
  • Belly pain.
  • Nausea and fullness in the upper stomach.
  • Flatulence (passing gas frequently) and bloating.
  • Lost appetite (anorexia).
  • Mucus in the stool (white fuzzy coating on a stool).

Food allergy is a different form of abnormal body reaction to food. Some food constituents may trigger an allergic or immune reaction, leading to gut-related and allergy-related symptoms.

The differences are in the table below.

Food intoleranceFood allergy
Affects 15-20% of the populationAffects nearly 2-5% of adults
Difficulty digesting certain types of food (not immune-mediated allergy).An immune-mediated reaction to certain foods or food components.
Diarrhea is often random (you will get diarrhea every time you eat the offending food).Usually causes acute attacks related to the ingestion of offending food.
Intestinal symptoms: diarrhea, extensive gas, bloating, and abdominal painIntestinal symptoms are the same
No extraintestinal symptomsExtraintestinal symptoms include rashes, urticaria, swollen lips, face, or life-threatening allergic reactions.
The severity of your symptoms is proportional to the amount you eat from the offending food.Even trace amounts of the offending food can produce severe symptoms.

Common offending foods:

  • Lactose intolerance (dairy products).
  • Fructose malabsorption.
  • Alcohol intolerance.
  • FODMAP intolerance (as with People with IBS).

Common offending foods: (examples)

  • Raw meat, seafood.
  • Nuts, peanut
  • Mustard.
  • Rice
  • Some vegetables and fruits.

Learn more about food intolerance and food allergy.

5. Inflammatory Bowel disease.

Inflammatory bowel diseases are divided into two distinctive conditions:

  • Crohn’s disease: inflammation and ulcers at any part of your digestive tract(from the moth to theianal area), but the common location of Crohn’s is the lower right abdomen (as it commonly affects the terminal part of the small intestine, which is called the ileum) (ref).
  • Ulcerative colitis: inflammations and ulcers affect the large intestine. The common location of Ulcerative colitis is the lower left abdomen (as it commonly affects the rectum and sigmoid colon) (ref).

Symptoms of Inflammatory Bowel disease include:

  • Diarrhea is commonly associated with blood and mucus. The diarrhea is more severe and persistent and can occur through remissions and exacerbations.
  • The stool can contain mucus only (as a white fuzzy coat) or mucus and blood.
  • Intense abdominal pain.
  • Fever, weight loss may present.
  • Fatigue, anorexia, nausea.

Learn More about IBD.

6. Celiac disease.

Celiac disease is an extreme example of food intolerance. In celiac disease, your body is sensitive to a protein called gluten (in wheat, rye, and barley).

Eating gluten results in severe intestinal inflammation and the secretion of lots of mucus. Mucus in stool can form a white fuzzy coating the stool.

Diarrhea doesn’t occur in all cases of celiac disease; it affects only 45-85% of the patients. So, mucus in stool can occur without diarrhea in patients with celiac disease.

People with celiac disease improve dramatically after cutting off the offending foods.

Symptoms of celiac disease:

  • Chronic diarrhea.
  • Bloating and gas.
  • Nausea, loss of appetite.
  • Weight loss.
  • Anemia (can be severe if left untreated).
  • Abdominal pain.
  • In rare cases, it can cause constipation.

7. Proctitis.

Proctitis is the inflammation of the rectum. Proctitis can cause excess mucus secretion in the last part of the colon and the rectum.

This will manifest as a white fuzzy coating on your stool. Also, mucus can come out without stool.

A characteristic symptom of proctitis is the constant or recurrent urge to poop with the passage of mucus or tiny stool amounts.

Causes of proctitis include:

  • Dysentery.
  • Inflammatory bowel diseases affect the rectum (Crohn’s or ulcerative colitis).
  • Sexually transmitted disease of the rectum.
  • Anal fissures.
  • Hemorrhoids (especially when they become inflamed.
  • IBS.
  • Rectal polyps and ulcers.
  • Rectal cancer.

Learn more about proctitis here.

8. Others.

The previous causes represent the most common and significant causes of white fuzzy causes. However, this song can carry way more possibilities.

Other possible causes include:

  • Cystic fibrosis.
  • Diverticular disease.
  • Certain medications (especially medications that trigger diarrhea).
  • Colorectal cancer.
  • Radiation therapy.
  • Eosinophilic proctitis.
  • And others.

When to see a doctor for a white fuzzy coating on your stool?

  • Abnormal large amounts of white fuzzy coating on your stool.
  • Constant notice of mucus for weeks or months.
  • Associated abdominal pain.
  • Associated changes in bowel movements (diarrhea or constipation).
  • Associated fever or body aches.
  • Associated Nausea, vomiting, or loss of appetite.
  • Associated weight loss.’
  • Associated blood in the stool.