Common Digestive Diseases
About the Digestive System
The human digestive system, (also known as the digestive tract, the gastrointestinal or GI tract, the alimentary canal) is a series of connected organs leading from the mouth to the anus. The digestive system allows us to break down the food we eat to obtain energy and nourishment. The digestive system -- which can be up to 30 feet in length in adults -- is usually divided into eight parts: the mouth, the esophagus, the stomach, the small intestine (or "small bowel") and the large intestine (also called "large bowel" or "colon") with the liver, pancreas, and gall bladder adding secretions to help digestion. These organs combine to perform six tasks: ingestion, secretion, propulsion, digestion, absorption, and defecation.
For more information on these digestive diseases and to find a doctor in your area, visit www.asge.org.
Colorectal cancer (CRC), often referred to as colon cancer, develops in the colon or the rectum (known as the large bowel or large intestine). The colon and rectum are parts of the digestive system also called the gastrointestinal (GI) tract. The digestive system processes food for energy and eliminates solid waste. CRC usually develops slowly over many years. Most colorectal cancer begins as a noncancerous (benign) adenoma or polyp (abnormal growth) that develops on the lining of the colon or rectum. Polyps can be removed to significantly reduce cancer risk. Colonoscopy plays an important role in colorectal cancer prevention because precancerous polyps can be detected and removed during the same exam when they are discovered. Click here to read a patient education brochure from the American Society for Gastrointestinal Endoscopy on colorectal cancer
To learn more about colorectal cancer screening and prevention, log on to the American Society for Gastrointestinal Endoscopy's colorectal cancer awareness Web site.
Polyps are benign growths (noncancerous tumors or neoplasms) involving the lining of the bowel. They can occur in several locations in the gastrointestinal tract but are most common in the colon. They vary in size from less than a quarter of an inch to several inches in diameter. They look like small bumps growing from the lining of the bowel and protruding into the lumen (bowel cavity). They sometimes grow on a "stalk" and look like mushrooms. Some polyps can also be flat. Many patients have several polyps scattered in different parts of the colon. Some polyps can contain small areas of cancer, although the vast majority of polyps do not. Click here to read a patient education brochure from the American Society for Gastrointestinal Endoscopy on colon polyps.
Gastroesophageal Reflux Disease (GERD)
Gastroesophageal reflux occurs when contents in the stomach flow back into the esophagus. This happens when the valve between the stomach and the esophagus, known as the lower esophageal sphincter, does not close properly. Common symptoms of gastroesophageal reflux disease are heartburn and/or acid regurgitation. Heartburn is a burning sensation felt behind the breast bone that occurs when stomach contents irritate the normal lining of the esophagus. Acid regurgitation is the sensation of stomach fluid coming up through the chest which may reach the mouth. Less common symptoms that may also be associated with gastroesophageal reflux include unexplained chest pain, wheezing, sore throat and cough, among others. Click here to read a patient education brochure from the American Society for Gastrointestinal Endoscopy on GERD.
Barrett's Esophagus and Esophageal Cancer
Barrett's esophagus is a condition in which the lining of the esophagus changes, becoming more like the lining of the small intestine rather than the esophagus. This occurs in the area where the esophagus is joined to the stomach. It is believed that the main reason that Barrett's esophagus develops is because of chronic inflammation resulting from Gastroesophageal Reflux Disease (GERD). Barrett's esophagus is more common in people who have had GERD for a long period of time or who developed it at a young age. It is interesting that the frequency or the intensity of GERD symptoms, such as heartburn, does not affect the likelihood that someone will develop Barrett's esophagus. Most patients with Barrett's esophagus will not develop cancer. In some patients, however, a precancerous change in the tissue, called dysplasia, will develop. That precancerous change is more likely to develop into esophageal cancer. For more information, click here to read a patient education brochure from the American Society for Gastrointestinal Endoscopy on Barrett's esophagus and esophageal cancer.
Diverticulosis is a condition in which there are small pouches or pockets in the wall or lining of any portion of the digestive tract. These pockets occur when the inner layer of the digestive tract pushes through weak spots in the outer layer. A single pouch is called a diverticulum. The pouches associated with diverticulosis are most often located in the lower part of the large intestine (the colon). Some people may have only several small pouches on the left side of the colon, while others may have involvement in most of the colon. Click here to read a patient education brochure from the American Society for Gastrointestinal Endoscopy on diverticulosis.
Celiac disease, also called celiac sprue, is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley. Gluten is found mainly in foods, but is also found in products we use every day, such as stamp and envelope adhesive, medicines, and vitamins. When people with celiac disease eat foods containing gluten, their immune systems respond by damaging the small intestine. This injury occurs to tiny fingerlike protrusions, called villi, which line the small intestine, and are critical in allowing absorption of nutrients and preventing malnutrition. Click here to read a fact sheet from the American Society for Gastrointestinal Endoscopy about celiac disease.
The pancreas is a gland deep in the abdomen, behind the stomach, that is part of the digestive and endocrine systems. It is situated near the liver, gallbladder (where bile is stored) and the beginning of the small intestine (duodenum). The pancreas makes juices that help with digestion (enzymes) as well as important hormones such as insulin that control the level of sugar in the bloodstream. PC is a condition in which cells are allowed to grow and form a collection of abnormal cells known as a mass or tumor. Over time the mass continues to grow without heeding the body's usual checkpoints. Not all masses are cancerous, a benign condition known as chronic pancreatitis can simulate cancer of the pancreas. Sometimes instead of forming a solid mass PC can begin as a collection of fluid known as a cyst (most cysts however are not cancerous, they are benign).
Click here to read a fact sheet from the American Society for Gastrointestinal Endoscopy about pancreatic cancer.
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