Question: What is (are) Microscopic Colitis: Collagenous Colitis and Lymphocytic Colitis ?
Answer: Microscopic colitis is an inflammation of the colon that a health care provider can see only with a microscope. Inflammation is the bodys normal response to injury, irritation, or infection of tissues. Microscopic colitis is a type of inflammatory bowel diseasethe general name for diseases that cause irritation and inflammation in the intestines. The two types of microscopic colitis are collagenous colitis and lymphocytic colitis. Health care providers often use the term microscopic colitis to describe both types because their symptoms and treatments are the same. Some scientists believe that collagenous colitis and lymphocytic colitis may be different phases of the same condition rather than separate conditions. In both types of microscopic colitis, an increase in the number of lymphocytes, a type of white blood cell, can be seen in the epitheliumthe layer of cells that lines the colon. An increase in the number of white blood cells is a sign of inflammation. The two types of colitis affect the colon tissue in slightly different ways: - Lymphocytic colitis. The number of lymphocytes is higher, and the tissues and lining of the colon are of normal thickness. - Collagenous colitis. The layer of collagen, a threadlike protein, underneath the epithelium builds up and becomes thicker than normal. When looking through a microscope, the health care provider may find variations in lymphocyte numbers and collagen thickness in different parts of the colon. These variations may indicate an overlap of the two types of microscopic colitis.
Source: NIDDK

Question: What is (are) Microscopic Colitis: Collagenous Colitis and Lymphocytic Colitis ?
Answer: The colon is part of the gastrointestinal (GI) tract, a series of hollow organs joined in a long, twisting tube from the mouth to the anusa 1-inch-long opening through which stool leaves the body. Organs that make up the GI tract are the - mouth - esophagus - stomach - small intestine - large intestine - anus The first part of the GI tract, called the upper GI tract, includes the mouth, esophagus, stomach, and small intestine. The last part of the GI tract, called the lower GI tract, consists of the large intestine and anus. The intestines are sometimes called the bowel. The large intestine is about 5 feet long in adults and includes the colon and rectum. The large intestine changes waste from liquid to a solid matter called stool. Stool passes from the colon to the rectum. The rectum is 6 to 8 inches long in adults and is between the last part of the coloncalled the sigmoid colonand the anus. During a bowel movement, stool moves from the rectum to the anus and out of the body.
Source: NIDDK

Question: What causes Microscopic Colitis: Collagenous Colitis and Lymphocytic Colitis ?
Answer: The exact cause of microscopic colitis is unknown. Several factors may play a role in causing microscopic colitis. However, most scientists believe that microscopic colitis results from an abnormal immune-system response to bacteria that normally live in the colon. Scientists have proposed other causes, including - autoimmune diseases - medications - infections - genetic factors - bile acid malabsorption Autoimmune Diseases Sometimes people with microscopic colitis also have autoimmune diseasesdisorders in which the bodys immune system attacks the bodys own cells and organs. Autoimmune diseases associated with microscopic colitis include - celiac diseasea condition in which people cannot tolerate gluten because it damages the lining of the small intestine and prevents absorption of nutrients. Gluten is a protein found in wheat, rye, and barley. - thyroid diseases such as - Hashimotos diseasea form of chronic, or long lasting, inflammation of the thyroid. - Graves diseasea disease that causes hyperthyroidism. Hyperthyroidism is a disorder that occurs when the thyroid gland makes more thyroid hormone than the body needs. - rheumatoid arthritisa disease that causes pain, swelling, stiffness, and loss of function in the joints when the immune system attacks the membrane lining the joints. - psoriasisa skin disease that causes thick, red skin with flaky, silver-white patches called scales. More information is provided in the NIDDK health topics: - Celiac Disease - Hashimotos Disease - Graves Disease Medications Researchers have not found that medications cause microscopic colitis. However, they have found links between microscopic colitis and certain medications, most commonly - nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen - lansoprazole (Prevacid) - acarbose (Prandase, Precose) - ranitidine (Tritec, Zantac) - sertraline (Zoloft) - ticlopidine (Ticlid) Other medications linked to microscopic colitis include - carbamazepine - clozapine (Clozaril, FazaClo) - dexlansoprazole (Kapidex, Dexilant) - entacapone (Comtan) - esomeprazole (Nexium) - flutamide (Eulexin) - lisinopril (Prinivil, Zestril) - omeprazole (Prilosec) - pantoprazole (Protonix) - paroxetine (Paxil, Pexeva) - rabeprazole (AcipHex) - simvastatin (Zocor) - vinorelbine (Navelbine) Infections Bacteria. Some people get microscopic colitis after an infection with certain harmful bacteria. Harmful bacteria may produce toxins that irritate the lining of the colon. Viruses. Some scientists believe that viral infections that cause inflammation in the GI tract may play a role in causing microscopic colitis. Genetic Factors Some scientists believe that genetic factors may play a role in microscopic colitis. Although researchers have not yet found a gene unique to microscopic colitis, scientists have linked dozens of genes to other types of inflammatory bowel disease, including - Crohns diseasea disorder that causes inflammation and irritation of any part of the GI tract - ulcerative colitisa chronic disease that causes inflammation and ulcers in the inner lining of the large intestine More information is provided in the NIDDK health topics: - Crohns Disease - Ulcerative Colitis Bile Acid Malabsorption Some scientists believe that bile acid malabsorption plays a role in microscopic colitis. Bile acid malabsorption is the intestines inability to completely reabsorb bile acidsacids made by the liver that work with bile to break down fats. Bile is a fluid made by the liver that carries toxins and waste products out of the body and helps the body digest fats. Bile acids that reach the colon can lead to diarrhea.
Source: NIDDK

Question: How to prevent Microscopic Colitis: Collagenous Colitis and Lymphocytic Colitis ?
Answer: Researchers do not know how to prevent microscopic colitis. However, researchers do believe that people who follow the recommendations of their health care provider may be able to prevent relapses of microscopic colitis.
Source: NIDDK

Question: Who is at risk for Microscopic Colitis: Collagenous Colitis and Lymphocytic Colitis? ?
Answer: No. Unlike the other inflammatory bowel diseases, such as Crohns disease and ulcerative colitis, microscopic colitis does not increase a persons risk of getting colon cancer.
Source: NIDDK