Crohn's Disease: Mucus in the Stool

  • 1st Revision: Adam M Lane[Linkedin]
  • 2nd Revision: Kaamya Mehta[Linkedin]
  • 3rd Revision: Tolulope Ogunniyi

What is Inflammatory Bowel Disease?

Inflammatory bowel disease, known as IBD, is a term mainly used to describe two conditions: Crohn's disease and ulcerative colitis, which causes inflammation of your gut. 

Irritable bowel syndrome is a common condition that affects your gut, causing stomach cramps, bloating, loose stools and/or constipation. The exact cause of IBS is unknown, but changes in diet and medicines can help to control the symptoms. The tests to rule out IBS generally consists of blood tests and a poo sample to check for infections or irritable bowel diseases, like ulcerative colitis or Crohn's. 

Ulcerative colitis is a disease where your large bowel and rectum become inflamed. Small ulcers can be formed in your large bowel and rectum, producing bleeding and blood. The main symptoms of ulcerative colitis are diarrhoea, faces with blood, mucus or pus, stomach ache, the need to empty your bowel often, fatigue, and weight loss.3The symptoms may not be there altogether, and you may have periods with mild or no symptoms, known as remission, or times where your symptoms are present for days or weeks, known as relapses or flare-ups. In severe cases, when you open your bowels six times a day, you may also experience shortness of breath, high temperature, and more blood in your stools. 

Crohn's disease is a lifelong condition where parts of your bowel become swollen and ulcerated, and it belongs to the so-called irritable bowel disease (IBD). Your immune system starts attacking your gut, causing pain, ulcers and inflammation anywhere in your digestive system, with the end of the small bowel and beginning of the colon being the most common areas affected. Crohn's disease differs from ulcerative colitis, another IBD, but might have similar symptoms. The difference is that Crohn's disease can "skip" parts of your bowel, meaning that you can have healthy patches of the gut in-between areas affected. In contrast, ulcerative colitis does not present these healthy patches. There are also different types of Crohn's disease depending on the portion of your gut affected, with their particular presentation and symptomatology:

  • Ileocolitis: Affects the last part of your small bowel and the colon.
  • Ileitis: Only affects the last portion of the small bowel, known as the ileum.
  • Gastroduodenal: Affects the stomach and the beginning of the small bowel. 
  • Jejunoileitis: Affects the upper half of the small intestine, known as jejunum. 
  • Colitis: Affects just the large bowel, known as the colon. 

Signs and Symptoms

The signs and symptoms of Crohn's vary, depending on which part of the bowel is affected, but the most common may include:

  • Stomach cramps and pain, mainly in the lower right side of your abdomen.
  • Loose stools.
  • Blood in your poo.
  • Tiredness.
  • Weight loss.

And less common:

  • Raised temperature
  • Joint pain
  • Vomiting, sickness.

Symptoms might not be present altogether and not all the time. Crohn's disease often presents symptoms as relapses, meaning that you will experience periods where you will feel okay with mild or no symptoms and periods with more severe symptoms. 

Causes and Risk Factors

The exact cause of Crohn's disease remains unknown; however, hereditary and immune problems are likely to play a vital role:

  • Immune system: although it has been identified as an immune response behind Crohn's disease, it remains unclear why this is happening or what is triggering it.
  • Heredity: although Crohn's is more common in people with relatives affected by the disease, most people with Crohn's have no history in their family.

As mentioned earlier, it is still unclear what causes Crohn's disease, but the following risk factors have been identified:

  1. Age: Crohn's disease can occur at any age, but most cases are diagnosed before 30.
  2. Smoking: Directly linked with more severe cases of Crohn's and more risk of needing surgery.
  3. Family history: 1 out of 5 cases of Crohn's has a first-degree relative affected with this condition. 
  4. Ethnicity: Although it affects predominantly Caucasian individuals, an increase in cases among the Black population in the UK and the USA has been observed.
  5. Medication: Although they don't directly cause Crohn's disease, drugs like ibuprofen, naproxen, and diclofenac can cause swelling in your bowels and worsen symptoms.


Crohn's disease can be challenging to diagnose as its symptoms are familiar with many other conditions. Some tests to rule out Crohn's might include:8

  • Biopsy: A tiny piece of your bowel is taken and analysed to look for signs of Crohn's disease.
  • MRI and CT scan: They capture images of your body to help with diagnosis.
  • Colonoscopy: A tube with a camera is inserted through your back passage to check for inflammation in your bowels.
  • Complementary tests: Blood and poo sample.


Unfortunately, there is no current cure for Crohn's disease; however, there are different treatments to help reduce or stop the symptoms, being medication the most common and surgery the less:


  1. Steroids: They reduce the inflammation of your bowel, generally for two weeks. Side effects: weight gain, risk of infections.
  2. Immunosuppressants: Second-line treatment when steroids don't help decreases the activity of your immune system, so it doesn't attack the cells of your bowel; treatment can last months. 

Side effects: sickness, risk of infections, liver problems.

  • Biological medicines: Third line when the first two don't work, generally they are long-term treatment through months or years. 

Side effects: risk of infections, pain in joints, fever, itching.

  • Surgery: when the medication is not working, or the benefits outline the risks. The procedure is called resection, where they cut up a piece of your bowel with Crohn's and rejoin the healthy parts together. Generally, this operation involves small cuts in your tummy, usually done under general anaesthesia, meaning that you will be asleep. Depending on the part of your bowel affected or the size of the bowel that needs to be removed, you may end up with a colostomy: a little hole in your tummy where the poop comes out and gets collected in a bag. This is generally for a few months until your bowel recovers properly and gets healthy. 


Diet is an essential part of treating Crohn's disease. It's important to remain well hydrated and nourished with a well-balanced diet. Depending on the stage of your Crohn's disease, recent studies have shown:10

During remission (mild or no symptoms): 

  1. Fibre: Good in prebiotics, which may improve the balance of good bacteria in your gut. It can also help you to keep in remission longer.
  2. Protein: Avoid red meat, bacon, and sausages and focus on fish, eggs, nuts and tofu. 
  3. Fruits and vegetables
  4. Calcium: Dairy and kale, broccoli, almonds, white beans.

During flare-ups or relapses:

  1. Avoid spicy, flatulent, greasy and fried food, dairy, sugary, caffeine and alcohol.
  2. Try refined grains (white rice, noodles, pasta), lean protein (poultry, eggs, pork), low-fibre fruit (banana, grape, melon), and well-cooked vegetables (carrots, squash, potatoes), and oral supplements. 

It is also essential to modify your meal strategies and not stick to the traditional three-meals-a-day pattern. Try the following:

  • Eat smaller portions so it can help your intestines to absorb nutrients. 
  • Drink 2 litres of water daily. 
  • Avoid chewing gum between meals, and reduce the accumulation of gas in your intestines.
  • Cook foods simply. Choose steaming, boiling, poaching or grilling.

What to do if I have mucus in my stools?

A small amount of mucus is average as it helps to keep your intestine moist and lubricated. It is essential to contact your doctor if there is more mucous in your faeces than usual or if it is accompanied by blood and/or a change in your bowel habits.

Yellow Stools

It is usual for your stools to change their colour, normally due to changes in your diet. However, sometimes the cause may be a health problem:

  • Liver and gallbladder problems: stones, cirrhosis.
  • Pancreatic issues: cancer, cysts, blockages. 
  • Celiac disease.
  • Infections.
  • Gilbert's syndrome.
  • Stress.
  • Diet.

Fat Malabsorption

Fat malabsorption may be the reason why your stools turn yellow or pale. Fats that aren't absorbed in the small intestine pass to your colon, causing fatty stools. Fatty stools are particularly smelly and runny.13 Fat malabsorption is sometimes caused by inflammation in your intestines, like Crohn's disease. If your small intestine is affected by Chron's or any other inflammatory disease, it is likely that fat absorption may be affected.14


Irritable bowel disease, known as IBD, are long-term conditions that affect your digestive tract causing swelling and ulcers. They involve two main requirements: Crohn's disease and ulcerative colitis, both cause similar symptoms, and the difference is that Crohn's leaves healthy patches in the intestines while ulcerative colitis doesn't, having a continuous part of the intestine affected. The cause of ulcerative colitis and Chron's remain unknown, but it is believed that your immune system and genes play an essential role in developing these diseases. Crohn's diagnosis can be difficult, so you may need to have several tests carried out. At the same time, treatment depends on the severity of the disease and the portion of the intestine affected. Although incurable, Chron's symptoms, including relapses and remissions, can be managed with medication, diet and healthy habits. Diet is an integral part of controlling your Crohn's symptoms, as it can reduce the severity of the signs and the number of relapses. Sometimes Crohn's disease can cause your stools to turn into a pale/yellowish colour, produced by the malabsorption of fats in the small intestine.


  1. Irritable bowel syndrome (Ibs) [Internet]. 2017 [cited 2022 Jul 8]. Available from:
  2. Irritable bowel syndrome (Ibs) - Getting diagnosed [Internet]. 2018 [cited 2022 Jul 8]. Available from:
  3. Ulcerative colitis [Internet]. 2018 [cited 2022 Jul 8]. Available from:
  4. Crohn’s Disease [Internet]. [cited 2022 Jul 8]. Available from:
  5. Overview of crohn’s disease [Internet]. Crohn’s & Colitis Foundation. [cited 2022 Jul 8]. Available from:
  6. Crohn’s disease – Symptoms – NHS [Internet]. 2017 [cited 2022 Jul 8]. Available from:
  7. Crohn’s disease - Symptoms and causes [Internet]. Mayo Clinic. [cited 2022 Jul 8]. Available from:
  8. Crohn’s disease – Diagnosis – NHS [Internet]. 2017 [cited 2022 Jul 8]. Available from:
  9. Crohn’s disease – Treatment – NHS [Internet]. 2017 [cited 2022 Jul 8]. Available from:
  10. Reich MR, M.D. Crohn’s disease diet: what you can and can’t eat [Internet]. [cited 2022 Jul 8]. Available from:
  11. Mucus in stool: A concern? [Internet]. Mayo Clinic. [cited 2022 Jul 8]. Available from:
  12. Yellow poop: causes, meaning, and treatment [Internet]. Healthline. 2015 [cited 2022 Jul 8]. Available from:
  13. Malabsorption(Syndrome) [Internet]. Cleveland Clinic. [cited 2022 Jul 8]. Available from:
  14. Malnutrition and ibd [Internet]. Crohn’s & Colitis Foundation. [cited 2022 Jul 8]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.

Eduardo Bondia-Marion

Masters of Public Health - MIPH, Liverpool School of Tropical Medicine

Eduardo is an Associate Lecturer in Nursing and graduate in International Public Health with strong experience in clinical roles between the hospital and community sectors.
He has more than 10 years experience as registered nurse and more recently as an associate lecturer at The Open University.

Leave a Reply

Your email address will not be published. Required fields are marked * presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818