Crohn’s disease. In the early 1950s, it was recognized that Crohn’s disease did not necessarily affect just the ileum, but that other parts of the gastrointestinal tract, such as the colon or large intestine, could be affected.
Ulcerative Colitis
Like Crohn’s disease, ulcerative colitis had probably been with us for some time before it was fully described in the late 19th century. Ulcerative colitis is sometimes referred to as ulcerative proctitis, ulcerative proctosigmoiditis, or ulcerative pancolitis. These names relate primarily to the extent of the inflammation of the colon rather than to any fundamental differences in the presumed causes of ulcerative colitis. In the first half of the 20th century, the treatment of ulcerative colitis was surgical, and many patients ended up dying of complications of the disease or the surgery. Since the 1940s, there has been a consistent improvement in the surgical and medical management of ulcerative colitis, and death due to complications of the disease or its treatment is now exceedingly rare.
Limited Inflammation
In ulcerative colitis, the inflammation is limited to the large intestine, which includes the rectum. The rest of the gastrointestinal tract is not involved.
Irritable Bowel Syndrome
Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are often confused since their names are so alike. IBS is a poorly understood condition of the gastrointestinal tract. Although IBS is characterized by chronic abdominal discomfort or pain and an alteration in the normal bowel habit, it is quite a different condition from Crohn’s disease and ulcerative colitis (IBD).
In IBS, it is thought that the problems arise from a change in the way the bowel functions or the way in which the brain senses the bowel functioning. In IBS, there has been no clear or consistent evidence that inflammation plays a role in causing the symptoms in humans. This is different from IBD, where inflammation is the main defining characteristic of the disease, and where treatment against inflammation will help treat the disease and alleviate its symptoms. In IBS, treatment is usually aimed at modifying the motility of the gastrointestinal tract or the transmission of the pain impulses from the intestine to the brain.
Glossary of Inflammatory Bowel Disease
Gastroenterologists use several technical terms to describe IBD. You can start to use the language of this disease in discussions with your health-care providers. These terms are defined more thoroughly in their context later in the book.
Abscess: a localized collection of dead and infected tissue (pus), which typically becomes liquid. The consequences may be serious if 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:
