When we talk about digestive health, we often hear about inflammation. There’s no doubt that this word has become a popular one in health care in recent years. As a gut health dietitian at Ignite Nutrition, I am particularly interested in how inflammation affects our digestion and how we can use nutrition to help manage GI inflammation, especially in rare conditions, like microscopic colitis.
Microscopic colitis is a type of inflammatory bowel disease (IBD) characterized by diarrhea, cramping and pain. It is generally milder than other types of IBD such as ulcerative colitis or Crohn’s disease, but can be bothersome enough to require attention!
Today we’ll be reviewing microscopic colitis in detail; everything from diagnosis to long-term management. Let’s jump in!
Defining Microscopic Colitis
Microscopic colitis falls into the wider category of inflammatory bowel disease, which includes various disorders that involve chronic inflammation of the digestive tract. The main difference with microscopic colitis compared to other types of IBD is that the inflammation is smaller scale (hence ‘microscopic’) and therefore not as visible in certain tests and imaging. Once thought to be quite rare, microscopic colitis is now diagnosed in approximately 20% of chronic diarrhea patients that undergo colonoscopy.1
There are two subtypes of microscopic colitis, lymphocytic colitis and collagenous colitis. Both conditions are similar in presentation, but each have unique characteristics as well. Due to the very similar symptoms, the difference is identified via microscopic diagnosis only.
Collagenous colitis – Although this version of the disease can be seen in all age groups, it is primarily diagnosed in middle-aged women, typically between ages 50-70.1 In collagenous colitis, a thickened band of collagen (a type of protein) forms underneath the most inner layer of the large bowel called the epithelium. Extra deposits of collagen in the lining of the colon have an inflammatory effect, causing watery diarrhea. Researchers are still working to understand the reasoning for this occurrence in certain populations.2
Lymphocytic colitis – Similar to collagenous colitis, this subtype is mostly diagnosed in the middle aged population, but is more evenly diagnosed in both men and women.2 Also resulting in chronic diarrhea, lymphocytic colitis does not involve a thickening of collagen but rather an abundance of something else – lymphocytes. Also found below the epithelium of the large bowel, lymphocytes are white blood cells that are actually supposed to help with immunity. However, an increased volume in the tissue of the colon can ultimately lead to inflammation and therefore symptoms.
Symptoms of microscopic colitis
Both subtypes of microscopic colitis typically have the same symptoms. The primary symptom is chronic, watery, non-bloody diarrhea. This can be either intermittent or ongoing depending on the individual.3 Other common symptoms associated with microscopic colitis include:
- Unintentional weight loss
- Abdominal pain
- Nocturnal diarrhea
- Electrolyte imbalances/deficiencies
Due to overlapping symptoms, microscopic colitis is often misdiagnosed as diarrhea-predominant IBS. Without proper diagnostic measures, they appear very similar! It is important to work with your family doctor and a gastroenterologist to undergo appropriate imaging and testing, as misdiagnosis may result in poor management outcomes. In our practice, we usually find diarrhea with microscopic colitis is sudden onset, is more severe than typical IBS, and unintentional weight loss accompanies microscopic colitis – though this isn’t always the case.
How is microscopic colitis diagnosed?
As the name implies, microscopic colitis involves inflammation on a very small scale – so small that it is difficult to see in traditional imaging such as MRIs, CT scans, and ultrasounds. It is common for an individual to first undergo these types of tests to rule out other functional digestive disorders. However, radiologic and laboratory tests generally come back normal in microscopic colitis.3
Therefore, the next step is for a gastroenterologist to perform a colonoscopy. Again, it can be difficult to identify microscopic colitis from a colonoscopy alone – the inner membrane of the large bowel generally appears quite normal on the surface. It is important that a few biopsies of the colon also be taken during colonoscopy – meaning small samples of the intestinal lining are removed for further examination.
These mucosal samples are then examined under a microscope to detect either the presence of excess collagen or excess lymphocytes – confirming either collagenous or lymphocytic colitis respectively.
Management of microscopic colitis
At this point in time, there is no cure for microscopic colitis. Instead, the focus of therapy is to enter and maintain remission of symptoms. Overall, the goal is to improve each individual’s quality of life – less pain, less urgency, and less trips to the washroom!
Remission of microscopic colitis is primarily achieved via pharmacological therapy, but the larger picture is also important. At Ignite Nutrition, we make it a priority to take a holistic approach to gut health, meaning we also discuss food and nutrition, stress, and other lifestyle factors that could be impacting the course of the disease. What specific options are out there for the treatment of microscopic colitis? Let’s review:
There are a few key drugs used in the treatment of microscopic colitis. Your physician will choose the most appropriate choice for you based on the severity and course of your symptoms. The most commonly prescribed medications include:
- Bismuth subsalicylate – Commonly known as Pepto-bismol, this drug acts as an antidiarrheal and is therefore a common management option for some people with microscopic colitis. It is a safe option that is often used as a first line therapy, although some individuals may need a stronger medication to fully see symptom relief.
- Budesonide/Entocort – This is a steroid generally used to manage moderate to severe presentations of microscopic colitis and has evidence to support its use in both subtypes of the disease.3 Budesonide is currently considered the best documented therapy for microscopic colitis, with many studies confirming its high success rates.1
- Loperamide – loperamide is an antidiarrheal drug often used to treat milder forms of microscopic colitis. Many doctors prescribe this as the first-line treatment prior to budesonide or other drugs, and many individuals see adequate relief with loperamide alone.3
- Prednisolone – Similar to budesonide, this drug is also a steroid. However, the research indicates a lower symptom remission rate with the use of this compared to budesonide. Additionally, there are more documented side effects with this medication.3
- Aminosalicylates – Sulfasalazine and mesalazine are less commonly used, but are gaining attention in the management of microscopic colitis. There is currently limited evidence, but the few studies that have been done have shown positive remission rates.
“I have microscopic colitis – should I change my diet?”
Excellent question! There aren’t currently any “gold standard” diets for those with microscopic colitis. However, there are some foods that may worsen diarrhea and other symptoms.
In particular, dietary secretagogues – a fancy term for foods that produce more secretions in the gut – are linked to increased diarrhea in those with microscopic colitis.3 Many people find that limiting intake of these types of foods helps them to find symptom relief. Examples of foods that are dietary secretagogues are:
- Lactose-containing foods
- Spicy foods
- High fat or deep-fried foods
The Low FODMAP Diet and Microscopic Colitis
The low FODMAP diet, a diet low in fermentable carbohydrates used in irritable bowel syndrome, is gaining more attention in the manage of IBD as well. Currently there are no studies that support the use of the low FODMAP diet in microscopic colitis specifically.
However, we have found that reducing FODMAPs that pull extra water into the bowel can often help to reduce incidence and severity of diarrhea. A trial of the low FODMAP diet may be appropriate but should be done under dietitian supervision. With the help of a registered dietitian, this elimination diet can be tailored personally to your microscopic colitis symptoms to ensure you are only avoiding the necessary foods.
Keep in mind, dietary triggers are very individualized. You may be completely fine with eating some or all of these foods! Ideally, we want to keep your diet the least restrictive possible, so you can get through life without all the food anxiety! A dietitian can help you to understand if there are any trigger foods you need to avoid to manage your microscopic colitis.
If you experience chronic diarrhea, it is important to discuss your symptoms with your family doctor. We need to break the stigma around talking about poop – generating conversation is the first step to getting answers! Discussing your symptoms with your physician ensures proper testing is done to confirm or rule out microscopic colitis as the cause of your diarrhea.
Additionally, if you have microscopic colitis, talking to a dietitian will help you to learn if your food choices are impacting your symptoms. Work with one of our Calgary-based registered dietitians today.
- Bohr et al. (2014). Diagnosis and management of microscopic colitis: current perspectives. Clinical and Experimental Gastroenterology, 201(4):7, 273-284
- Johns Hopkins Medicine. (2013).Collagenous and Lymphocytic Colitis [PDF file]. Retrieved from https://www.hopkinsmedicine.org/gastroenterology_hepatology/_pdfs/small_large_intestine/collagenous_lymphocytic_colitis.pdf
- Storr, M. A. (2013). Microscopic colitis: epidemiology, pathophysiology, diagnosis and current management – An update 2013. ISRN Gastroenterology, Article ID 352718, 12 pages, 2013. https://doi.org/10.1155/2013/352718.