Is Microscopic Colitis An Autoimmune Disease?
Microscopic colitis is an inflammatory disorder of the colon or your large intestine that leads to watery diarrhea & cramps. It is a type of inflammatory bowel disease, & not an autoimmune disease. It is called microscopic because the inflammation can only be seen under a microscope as it is too small to be seen with the naked eye. Lymphocytic & collagenous colitis are 2 kinds of known microscopic colitis. In lymphocytic colitis, the patients present with a growth in lymphocytes or wbc cells in the lining of the colon while in collagenous colitis the fibrous joining tissue below the epithelium becomes hard, that is also known as the collagen layer.
Causes & Symptoms Of Microscopic Colitis
Microscopic colitis is usually seen in people older than 50 years of age, especially those who suffer from a certain autoimmune disease such as rheumatoid arthritis, thyroid diseases, celiac illness & psoriasis. Some medicines that reduce inflammation (NSAIDs) like ibuprofen, aspirin & naproxen lead to microscopic colitis. Antacids & heartburn drugs, antidepressants & anti-cancer drugs cause colitis, while people with heart disease are more prone to microscopic colitis. Infections induced by viruses & bacteria lead to inflammation in the colon causing colitis. It is also known to run in families, affecting first degree relatives (hereditary). Chronic smokers are also at a risk of developing microscopic colitis.
Symptoms of Microscopic Colitis Include:
The most common symptom is diarrhea (non-bloody) that persists for time being. The person also has increased bowel movements. Other symptoms are consistent loss of weight, pain in abdomen (cramps), leaky stools due to increased mobility of bowel movements), dehydration, nausea due to bile acid mal-absorption that results in watery stools. Due to edema & inflammation of the colon’s lining there is less absorption of water from the undigested food, & the excess water is removed from the body as diarrhea along with pus & fluid & sometimes there can be bleeding from the lining of the colon due to ulcerations, which manifests as rectal bleeding.
Diagnosis of Microscopic Colitis
The patient usually gives a history of watery diarrhea that is associated with loss of weight, abdominal pain & fatigue without relief for more than two weeks. The confirmation of diagnosis is made with the help of multiple biopsies taken from different segments of colon from different regions. This is helpful in making an accurate diagnosis since one segment of colon might be abnormal while the other can be normal.
Microscopic colitis has a patchy distribution due to which flexible sigmoidoscopy is not enough to diagnose the condition since abnormalities of the disease may be absent from one segment of colon & present elsewhere. Thus, it is useful to take biopsies of other regions of the colon via colonoscopy to diagnose microscopic colitis.
What Is The Treatment For Microscopic Colitis?
Mostly microscopic colitis goes away on its own without any medical treatment. Your doctor might ask you to avoid foods & drinks that might aggravate your symptoms like caffeine & dairy products. Taking fiber supplements is helpful in most cases. In case the symptoms are not controlled then over the counter drugs to control diarrhea (Imodium & Pepto-Bismol) can be given. To reduce swelling sulfasalazine such as azulfidine is used or steroids are given.
Other drugs used to control colitis are mesalamine, cholecystramine, budenoside, & prednoisone. Immunosuppressive therapy is being used where patients fail to respond to steroids or when there is relapse of the disease. Azathioprine or 6-mercaptopurine & methotrexate are the drugs of choice. Surgical intervention is required when no medication provides relief to the patient.
Prognosis Of Microscopic Colitis
The prognosis of microscopic colitis remains unclear. In some patients (approx two-thirds) the diarrhea resolves spontaneously after several years while in others (one-third) the condition remains uncured. The patient experience persistent or intermittent diarrhea along with abdominal pain for many years without any relieve in the symptoms.
However, with some dietary changes (by avoiding artificial sugars & caffeine, eating milk free & gluten free diet & drinking plenty of liquids) certain people have shown benefits in the long run.
“Microscopic Colitis: A Review of Etiology, Treatment and Refractory Disease” by NCBI Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567062/
“Microscopic Colitis: Causes, Symptoms, and Treatment” by Cleveland Clinic Link: https://my.clevelandclinic.org/health/diseases/17729-microscopic-colitis
“Microscopic Colitis” by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Link: https://www.niddk.nih.gov/health-information/digestive-diseases/microscopic-colitis