In 1990 using genome-wide linkage analyses polymorphism in the CARD15 gene, encoding a NOD2 protein which is associated with a predisposition of the of Crohn’s disease development was discovered. Polymorphism can cause insufficient immune responses to gut bacteria which may lead to changes in the bacterial population in lamina propria that cause inflammation associated with Crohn’s disease.(4) 2.How common is this disease? Are there any particular susceptibility groups? People with Crohn’s disease often get diagnosed between the ages of 15 and 35, but it can affect males and females equally and at any age. The cause of this disease is still unknown. However, it appears that interaction of genetic factors, environmental factors and response of the immune system plays role in the development of this disease. About 20% of people with Crohn’s disease have blood relatives with IBD. In addition, environmental factors such as viruses, bacteria, cigarette smoke and other antigens in the environment may trigger an abnormal immune response.(4) Interestingly, Crohn’s disease appears to be more common in people in developed countries, people of Jewish heritage and more prevalent in Caucasians.(2)3.What are the disease symptoms? Inflammation associated with Crohn’s disease can develop anywhere in the gastrointestinal tract, but the lower part of the small intestine, ileum and the beginning of the large intestine is most commonly affected. Symptoms depend on part of the GI tract that is inflamed.(1) This disease affects people in different ways and symptoms can be mild to severe: stomach pain, diarrhea, weight loss, sometimes constipation, bleeding from the rectum, nausea, fatigue and fever. With inflammation in small intestine, it makes it harder to digest and absorb nutrients from the food. Poor absorption, lack of necessary nutrients and poor appetite can cause malnutrition in patients with Crohn’s disease. When Crohn’s disease affects small and large intestine it often results in severe diarrhea, which leads often to anemia, low levels of folic acid, vitamin B12 and iron. People with Crohn’s disease have inability to maintain normal weight because of deficiencies in nutrition. In addition to that, Crohn’s disease can cause inflammation of eyes, skin and joints, bile ducts and liver. In children, it may affect growth and sexual development. (2)4.What mechanisms are responsible for these disease symptoms?Crohn’s disease is a type of inflammatory bowel disease when immune system attacks and damages gastrointestinal system. It’s a long-term condition that affects body’s ability to intake in nutrients, digest food and get rid of waste. Scientists discovered a gene associated with Crohn’s disease. Mutation in this genes leads to abnormal reaction of the immune system toward some food, bacteria and other substances as foreign invaders causing chronic inflammation when white blood cells accumulating in the lining of the intestines which can lead to the development of ulcers.(2)5.How is the diagnosis made? What particular clinical tests are used to make this diagnosis? To diagnose Crohn’s disease physician has to take in consideration physical exams, lab tests, health history and family history of the patient. Various lab tests can be used to detect anemia, infection, inflammation and to identify deficiencies of vitamins or minerals: white blood cell counts, blood sedimentation rates test, red blood cell counts, body mineral levels, blood protein levels and stool samples to check for blood or infectious microbes. In addition, certain imaging tests can help to identify a location and the severity of Crohn’s disease. For instance, X-rays of abdominal area can identify narrowing of the intestines or blockage from scarring or inflammation in the intestines. Endoscopy can detect early problems associated with this disease. A barium X-ray used to find ulcers of small intestine and abnormal connections between organs that can’t be detected by other techniques. CT scan of the abdomen and pelvis can detect abscesses. A sigmoidoscopy of the lowest part of the large intestine and colonoscopy of the end of the small intestine and large intestines may be used to check for the signs of inflammation, bleeding and formation of ulcers. MRI can help to identify intestinal or anal fistula. (2)6.What is the prognosis for someone with this disease? Many people with Crohn’s disease are able to live normal lives, but symptoms can come and go. A patient may feel good for a while, but flare-ups may appear anytime. To avoid that, patients should make some adjustments to their life style and a diet. One of the most important precautions should be taken with foods that can trigger symptoms of Crohn’s disease which includes alcohol, carbonated beverages, coffee, tea, chocolate, nuts, oils, fatty food, spicy food, dairy products, raw vegetables and fruits, high fiber food, gas-producing food (beans, cabbage, broccoli, onions), red meat and pork. Patients should know how to avoid flare-ups and possible complications by controlling inflammation, achieving remission and maintaining remission. Female patients should be aware than this disease could affect their ability to get pregnant and may cause problems during pregnancy. (2)7.What are the treatment options? Although there is no cure for Chron’s disease, there is a variety of treatments to manage it. The purpose of treatments is to reduce inflammation, relieve symptoms of pain, diarrhea, bleeding and eliminate possible nutritional deficiencies. Treatment might involve drugs, nutritional supplements, surgeries depends on the location of the disease and severity of it. The first step of the treatment usually involves reducing inflammation. Many people first treated with Azulfidine, but if a person does not respond to this medication, drugs containing 5-ASA such as Asacol, Dipentum or Giazol may be prescribed. Corticosteroids such as prednisone usually prescribed to patients with moderate to severe symptoms. Immunosuppressants like MTX, Rheumatrex, Azasan or Prograf prescribed to decrease the activity of the immune system. (3) When a person with Crohn’s disease doesn’t respond to the standard treatments, corticosteroids and immunosuppressants, biologic drugs such as Remicade or Inflectra could be given intravenously. Other anti-TNF medications that may be used are Humira, Amjevita and Cimzia.(4) Antibiotics ciprofloxacin, ampicillin, tetracycline and metronidazole may be prescribed to treat bacterial infections. In addition, a physician may recommend over-the-counter medications such as pain relievers, antidiarrheal medications, nutritional supplements and fluid replacements to avoid dehydration.(2) If the disease doesn’t respond to medication, surgery may be an option. In fact, about 60%-75% of patients with Crohn’s disease may require surgery at some point to correct some of the complications such as repairing damage of intestines or clearing an intestinal blockage. (3) However, after surgery symptoms of Crohn’s disease can reappear so it’s essential to manage disease after the surgery.