Microscopic colitis: the overlooked cause of chronic watery diarrhoea

Microscopic colitis: An overlooked cause of chronic diarrhoea

Do you suffer from persistent, watery diarrhoea that affects your daily life? Many patients with these symptoms are mistakenly told they have irritable bowel syndrome (IBS). However, behind the frequent bathroom visits may lie a condition called microscopic colitis.

At Kirurgen.dk, we are experts in investigating gastrointestinal disorders. To make the correct diagnosis, a specialised bowel examination is necessary, as this disease cannot be seen with the naked eye.

What is microscopic colitis?

Microscopic colitis is a chronic inflammatory condition of the large intestine (colon). The unique aspect of this disease is that the lining of the bowel looks completely normal and healthy when viewed during a colonoscopy. The inflammation is hidden within the tissue itself and can only be detected by taking small tissue samples (biopsies), which are subsequently examined under a microscope.

The disease is divided into two types:

1. Collagenous colitis: A thickened layer of connective tissue (collagen) is seen beneath the mucous membrane.
2. Lymphocytic colitis: An accumulation of white blood cells (lymphocytes) is found in the lining of the bowel.

Both types produce the same distressing symptoms, particularly acute and severe diarrhoea.

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Symptoms you should react to

The primary sign of microscopic colitis is chronic, watery diarrhoea, which often occurs very suddenly. Other typical symptoms include:

• An urgency to pass stool that is difficult to control.
• The need for toilet visits during the night.
• Abdominal pain, bloating, and fatigue.
• Unintentional weight loss in severe cases.

If you experience these symptoms over a prolonged period, you should have a thorough bowel examination performed to determine the cause.

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Diagnosis requires a colonoscopy

Since the inflammation cannot be seen directly, a colonoscopy is the only certain way to reach a diagnosis. During a colonoscopy, we insert a flexible scope through the colon. Although the mucous membrane appears normal, we routinely take tissue samples from the right and left sides of the bowel.

This bowel examination is not only important for detecting microscopic colitis but also for ruling out other causes of diarrhoea, such as:

• Polyps or early stages of cancer.
• Crohn's disease or ulcerative colitis.
• Intestinal infections.

At Kirurgen.dk, we ensure that your colonoscopy takes place under safe and professional conditions, so you receive the fastest and most accurate answer regarding your symptoms.

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Treatment and advice

Once the diagnosis is made, effective treatment options are fortunately available:

• Medical treatment: Frequently, locally acting corticosteroids (Budesonide) are used, which effectively dampen the inflammation and stop your diarrhoea.
• Medication review: Certain types of medication (e.g., NSAIDs like Ibuprofen or certain types of acid pump inhibitors) can trigger the condition. We advise you on alternatives.
• Psyllium husk/calcium: A doctor-prescribed form of fiber/calcium supplement can help manage and stop diarrhoea.
• Diet: Although diet is not the cause, small adjustments can help provide bowel rest during the healing process.

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Scientific references (PubMed format)

• Münch A, Langner C, Magro F, et al. Microscopic colitis: European principles and recommendations for management. United European Gastroenterol J. 2020;8(3):261-281. doi: 10.1177/2050640620902341. PMID: 32212913.
• Pardi DS, Khanna S. Microscopic Colitis: An Update on Epidemiology, Pathogenesis, and Management. Am J Gastroenterol. 2023;118(11):1941-1951. doi: 10.14309/ajg.0000000000002447. PMID: 37552044.
• Kane JS, Ford AC. Microscopic Colitis: Diagnosis and Management. Gastroenterology. 2017;152(4):723-730. doi: 10.1053/j.gastro.2016.12.043. PMID: 28093238.
• Guagnozzi D, Lucendo AJ. Recent advances in the management of microscopic colitis. Expert Rev Gastroenterol Hepatol. 2020;14(1):31-43. doi: 10.1080/17474124.2020.1706481. PMID: 31854229.

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See also

Inflammatory bowel disease - overview · Bile acid malabsorption