Crohn's and Colitis. Dr. Hillary Steinhart

it is not quickly and properly managed; management involves draining the infected material and treating with antibiotics.

      Absorption: the digestive process of extracting nutrients from food and transferring these nutrients into the circulatory system; for example, the absorption of vitamin B₁₂ occurs in the ileum (the last section of the small intestine), which is often problematic in IBD.

      Anal sphincter: a muscular valve at the bottom of the rectum, which normally prevents stool from coming out when it is not supposed to. Damage to the sphincter or the nerves supplying the sphincter can lead to fecal incontinence.

      Colon (large intestine): the lower part of the gastrointestinal tract, which is primarily responsible for reabsorbing fluid and electrolytes (salts) from the stool.

      Colonoscopy: a diagnostic procedure for IBD that involves inserting a scope through the anus and rectum to the colon, where a tissue biopsy may be taken for testing.

      Distension: a significant increase in the size of the abdomen that may be due to gas, stool, or fluid.

      Duodenum: the first part of the small intestine, which receives ingested food after it has left the stomach. Although the duodenum is relatively short (about 12 inches/30 cm in length), it has an important role in the absorption of some nutrients, particularly iron; it is also the location where digestive enzymes from the pancreas and bile salts from the liver are first mixed together with food in order to help the digestion process.

      Enzyme: a protein that helps the rate of a chemical reaction, usually related to an important metabolic function of the body.

      Fecal incontinence: loss of the ability to hold stool (fecal waste). This may happen when there is inflammation of the rectum or lower part of the colon, or when there has been damage to the anal sphincter.

      Fistula: an abnormal communication or channel from the intestine to other organs or to the abdominal wall or skin.

      Gastroenterology: a medical specialty involved in the study of the digestive system, digestive disease, and digestive health.

      Gastrointestinal (GI) tract: the tract that extends from the mouth to the anus.

      Granuloma: a distinctive collection of inflammatory or immune cells that occurs in tissues affected by certain conditions, including Crohn’s disease.

      Ileum: the last part of the small intestine; it makes up about one-third of the entire length of the small intestine. Vitamin B₁₂ is absorbed here.

      Inflammatory bowel disease (IBD): any condition or disease that results in inflammation of the gastrointestinal tract, most commonly in the small and large intestine and the rectum.

      Irritable bowel syndrome (IBS): a functional GI syndrome characterized by symptoms of abdominal pain or discomfort, along with a change in the bowel habit. There is no inflammation of the GI tract.

      Jejunum: the second part of the small intestine, which makes up about two-thirds of the entire length of the small intestine and is responsible for the absorption of most of the nutrients from food.

      Lymphocyte: a type of white blood cell that is important in immune protection against a number of different possible bacteria and viruses that can cause infection.

      Motility: the movement of food through the GI tract.

      Mucosa: the inner lining of the gastrointestinal tract. The integrity of the mucosa is important for carrying out many of the roles of the gastrointestinal tract, particularly digestion of food and absorption of nutrients.

      Pancolitis: inflammation that involves the entire colon.

      Perforation: a hole in the wall of the intestine, which allows intestinal contents, often with numerous bacteria, into the abdominal cavity, where serious infection may result.

      Peristalsis: the involuntary contractions that move food through the GI tract.

      Proctitis: a form of colitis that affects only the rectum.

      Proteins: compounds made up of long chains of amino acids. Proteins are responsible for many critical functions, including maintenance of bodily structure and metabolic functions.

      Rectum: the very last part of the colon (large intestine), where stool is held before it is expelled. Inflammation of the rectum can result in difficulty holding stool for extended periods of time.

      Serosa: the outer lining (membrane) that covers the intestine.

      Stricture: a narrowing of the central channel in a segment of the intestine, which can lead to obstruction or blockage.

      Ulcer: an area in the gastrointestinal tract where there is a loss of the normal internal lining (mucosa). Ulcers can result in complications, such as bleeding or abscesses.

      Villi: fingerlike projections of the inner lining of the small intestine (mucosa), which have the effect of increasing the amount of mucosal surface available for absorption of nutrients.

       Smoking Paradox

      Smoking increases the risk of developing Crohn’s disease, and in those already affected, smoking may make the disease more aggressive or severe. In contrast, smoking seems to protect against ulcerative colitis. Patients with ulcerative colitis are more likely to be nonsmokers or former smokers than a similar group of people selected from the general population. In former smokers, the period soon after smoking cessation seems to be a time of particularly increased risk of developing ulcerative colitis. This observation has led some researchers to use nicotine, in the form of skin patches, as a treatment for ulcerative colitis. Despite the strong association between cigarette smoking and protection against ulcerative colitis, this approach to treatment has not been consistently effective.

Who Gets Inflammatory Bowel Disease?

      The onset of inflammatory bowel disease may be influenced by age, gender, and geography.

       Age Factors

      Crohn’s disease and ulcerative colitis most commonly begin in young people. Although it is unusual to see this disorder in children below the age of 5, there is an increase in the occurrence of IBD up until the age of 20, with maximum incidence in the age group between 20 and 40. It is less common, but certainly not unheard of, for older individuals in their 50s and 60s to first experience IBD. The first onset of disease is quite rare in the elderly. When symptoms first occur in someone from that age group, the attending doctor will usually consider other conditions or illnesses as more likely than IBD.

       Gender

      Inflammatory bowel disease appears to occur in males and females at roughly the same rate, although some studies have suggested that there may be slightly higher incidence in females. These differences may vary depending on the age of the first onset of IBD, but even if such differences exist, they are likely to be minor and of no major significance.

       Population Studies

      Although they are generally thought to be diseases that are found more frequently in developed countries, Crohn’s disease and ulcerative colitis have been observed in every race and in every country that has been specifically studied. There do appear to be some interesting differences between countries, as well as between ethnic groups within a given country.

      These diseases are much less common in Asia, but this may be changing. In Japan, for example, Crohn’s disease was almost unheard of over half a century ago, but there appears to have been a steady increase in the incidence since then. The incidence in the Jewish population is among the highest of any ethnic or racial group. However, within the Jewish population,