Your digestive system breaks down foods and liquids into their chemical components—carbohydrates, fats, proteins, and the like—that the body can absorb as nutrients and use for energy or to build or repair cells.
Food's journey through the digestive system begins in the mouth. It passes down the esophagus and into the stomach, where digestion begins. Next stop: the small intestine, which in the average person is more than 20 feet long. The small intestine further breaks down food, absorbs nutrients, and sends them into the bloodstream.
The remaining watery food residue moves into your large intestine, a muscular tube about 4 feet long. As undigested food passes through it, bacteria feed off the remnants. The wall of the large intestine soaks up most of the remaining water. Any undigested food that remains is expelled by a highly efficient disposal system.
Like all complicated machinery, the digestive tract doesn't always run smoothly. In some people, the problem is genetic. In others, the immune system mistakenly attacks the digestive system, causing various digestive woes. What we eat, and how we eat, can also throw off digestive health.
Common ailments of the digestive system include:
- heartburn, also known as gastroesophageal reflux disease (GERD)
- peptic ulcer
- diverticular disease
- irritable bowel syndrome (IBS)
- celiac disease
Keeping your digestive system healthy
There are several ways to keep your digestive system healthy:
- Don't smoke.
- Keep your weight in the healthy range.
- Eat a balanced, healthy diet.
- Exercise several times a week, if not every day.
- Learn different ways to reduce stress.
Digestive Health Articles
A newly-tested treatment for acute hepatitis C virus (HCV) may prevent the infection from developing into the chronic stage. The virus is the leading cause of liver disease in the United States.Researchers in Germany found acute HCV did not progress in 98 percent of infected study subjects who received interferon alfa-2b treatment, an antiviral protein. Their results also suggest the treatment is more effective, less expensive, and leads to fewer side effects than other known therapies. The study will be appearing in the New England Journal of Medicine's November 15, 2001, issue.During the first four weeks of the study, patients were injected with 5 million U of the drug daily, followed by 5 million U three times a week for the next 20 weeks. It took 3.2 weeks, on average, for levels of HCV to become undetectable in patients, and all 44 patients reached the undetectable mark at some point during therapy. After an additional 24 weeks of follow up, 42 of the 43 patients who completed the study still were still infection free.The researchers suggest 24 weeks of therapy for patients in the early part of the acute stage (fewer in patients whose serum levels of HCV quickly become undetectable), and 48 weeks of therapy for patients with chronic HCV. Though no serious side effects were noted, one person dropped out because of hair loss and flu-like symptoms.There is no standard treatment for acute HCV, and progression from acute to chronic occurs in 50%84% of cases. Chronic HCV infects almost 4 million people in the United States and about 170 million people worldwide. Cirrhosis of the liver develops in 1030 percent of those people.November 2001 Update
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An estimated 3.9 million people in the United States are infected with the hepatitis C virus (HCV). Hepatitis C affects the liver. In many but not all cases, hepatitis C progresses from mild to moderate inflammation (hepatitis), to scarring (fibrosis), to severe fibrosis with loss of liver function (cirrhosis), and finally liver failure. It is the leading cause of chronic liver disease and liver transplantation. But not all cases of hepatitis C progress to cirrhosis and the rate of progression of the disease is often unpredictable.The standard of care for treating hepatitis C is a combination of the antiviral drugs interferon-alpha and ribavirin. However, these drugs are not completely effective, they cause side effects, and they are expensive. Given the drugs' limitations and the unpredictable nature of disease progression, doctors remain in disagreement about whether treatment should begin at the onset of mild inflammation, or whether it should be delayed until a moderate amount of inflammation or cirrhosis exists.Using information from recent studies about the natural progression of HCV, researchers created a computer model that would help determine the optimal time to start combination antiviral drug therapy with interferon-alpha and ribavirin. The simulation projected that 18 percent of patients who had a liver biopsy every three years and started treatment at the onset of moderate inflammation would progress to cirrhosis after 20 years. This strategy avoided the need for treatment in 50 percent of patients, and increased life expectancy by 1.2 years. In patients who began treatment at the onset of mild inflammation, only 16 percent would progress to cirrhosis after 20 years, increasing life expectancy by another 0.4 years. In comparison, the computer model predicted that 27 percent of patients in the control group, which was left untreated, would have cirrhosis after 20 years.This study illustrated that beginning antiviral treatment at the onset of mild inflammation is the most effective treatment strategy. However, for patients with HCV and mild inflammation of the liver who do not wish to receive drug treatment or hope to delay it, biopsy management is also a reasonably effective option that could avoid treatment altogether.
Studies have linked Helicobacter pylori (H. pylori) infection with the development of gastric (stomach) cancer. H. pylori is a spiral-shaped bacterium that lives in the stomach and duodenum (the section of intestine just below the stomach). It has the ability to adjust to the harsh conditions in the stomach. H. pylori is believed to be transmitted orally.
Recently, researchers in Japan sought to clarify this association and explore which, if any, gastrointestinal conditions increase a person's risk of developing gastric cancer. The results of this study appeared in the September 13, 2001, issue of the New England Journal of Medicine.
The participants had duodenal (in the duodenum) ulcers, gastric ulcers, gastric hyperplasia (abnormal cell growth), or nonulcer dyspepsia (stomach pain). They underwent endoscopy for the early detection of cancer at enrollment and again during the next three years. Of the 1,526 who took part in the study, 1,246 had H. pylori infection and 280 did not.
Surgery for GERDIn recent years, people suffering from severe, chronic heartburn that cant be controlled with medications have turned to surgery with hopes for permanent relief and the prevention of esophageal cancer. But the results of a recent study that assessed the well being of patients a decade after they had surgery question its benefits.Heartburn, also known as gastroesophageal reflux disease (GERD), occurs when the opening between the esophagus and stomach relaxes spontaneously, allowing acidic gastric juices to flow into the esophagus and cause irritation. Medications for GERD include antacids, proton pump inhibitors that decrease the amount of acid produced, and drugs that increase the tightness of the esophageal. Surgery, an option usually reserved for hard-to-treat GERD, involves folding the top of the stomach around the end of the esophagus to create a tighter opening. This procedure has become more popular with the development of minimally invasive techniques.A study from the late 1980s of 247 heartburn patients found surgery was better than medication at controlling symptoms. However, ten years later a follow-up study of 239 of the original patients found many of the patients who underwent surgery still suffered from heartburn. Though their symptoms were less intense than those who received medication in the original study, 62% of the surgical patients still took antireflux medication regularly (compared to 92% of the medical patients).The study also found that surgery failed to significantly decrease the risk for esophageal cancer compared to treatment with medication. Chronic heartburn is a risk factor for this cancer. However, the small size of the study combined with the low incidence of esophageal cancer did not rule out the possibility of a difference. A more surprising result of the study showed surgical patients were more likely to die than patients on medication. These deaths were not related to the surgery, but close to half (48%) were related to heart disease. The researchers were unprepared for this result and therefore have no data to explain this finding.The results of this study suggest that while surgery may do a better job at controlling the symptoms of heartburn, it doesnt eliminate the need for medication or decrease cancer risk. In general, surgery should be seen as an option of last resort for those patients whose symptoms are hard to treat with medication.
June 2001 Update
Chronic myelogenous leukemia (CML), one of four main types of leukemia, strikes about 5,000 people every year. On average, patients live 3-4 years after receiving a diagnosis of CML. Last week, the FDA approved Gleevec (imatinib mesylate, also known as STI 571) as an oral treatment for CML.Gleevec has been shown to substantially reduce the level of cancerous cells in the bone marrow and blood of treated patients. In clinical trials, 90 percent of patients in the first phase of CML went into remission within the first six months of taking Gleevec. Of patients in the second phase of CML, 63 percent went into remission with Gleevec. The drug produced few side effects.Additional studies need to be done to determine how long the effects of this drug last, whether patients become resistant to the drug, and, most importantly, whether Gleevec can actually extend a patient's life.Still, the results are promising. Currently, the only cure for CML is a bone marrow transplant. Even if a patient is lucky enough to find a marrow donor match, the procedure is successful less than 2/3 of the time. Interferon, a widely used treatment for CML, can extend a patient's life for up to two years, but it has several serious side effects and does not cure the disease. Gleevec may be used in patients in the early stage of CML who do not respond to interferon therapy, and in patients in the later stages of CML.Most people with CML have a chromosomal abnormality, known as the Philadelphia chromosome, in which portions of two different chromosomes are switched. The result is the creation of an abnormal protein that allows the uncontrolled production of white blood cells, which can interfere with the function of other organs in the body. Gleevec blocks a signal sent out by the abnormal protein, thus blocking the rapid growth of white blood cells.The FDA's approval of the drug came after a surprisingly short 2½ months. Most drugs that, like Gleevec, are granted a priority review, take six months to approve. The approval was based on three separate studies that involved about 1,000 patients with CML. The drug has generated enthusiasm in the medical community because it targets a specific, cancer-causing protein, without damaging other cells.Scientists at an American Society of Clinical Oncology meeting announced earlier this month that Gleevec had also produced remission in 180 patients with advanced cases of an intestinal cancer known as gastrointestinal stromal tumor (GIST). Until now, GIST cancers have been incurable; GIST patients normally die within one year of receiving their diagnosis.May 2001 Update
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Breast-feeding has been linked to many advantages, including fewer earaches, colds, and asthma attacks. Now, a large trial involving almost 16,500 mother-infant pairs has shown even more benefits of breast-feeding. The study demonstrated that long-term, exclusive breast-feeding significantly decreases the risk of gastrointestinal tract infections and atopic eczema during a childs first year of life.Published in the Journal of the American Medical Association, the study involved mothers from the former Soviet republic of Belarus. To avoid a conflict of interest, given the advantages of breast-feeding that are already established, the program studied mothers who breast fed for a long time compared to mothers who breast fed for a short time then switched to bottle feeding. Some hospitals were randomly chosen to promote breast- feeding, through programs involving counseling from doctors and midwives; other hospitals, which served as a control group, provided the usual obstetric care. After 12 months, nearly 20% of the infants who were part of the breast-feeding program were still nursing, compared to 11.4% of the control group.In the first year, only 9% of the infants in the breast-feeding program had one or more gastrointestinal infection compared to about 13% of the control group. In addition, 3% of the breast-fed infants developed atopic eczema (a scaly, allergy-associated skin irritation), compared with 6% of the other babies.The World Health Organization recommends only breast milk for the first four to six months, and recommends that breast-feeding (in combination with formula) continue until 2 years of age. The American Academy of Pediatrics recommends breast milk alone until 6 months, and breast-feeding plus formula until 12 months old. This study suggests that breast-feeding exclusively for the first year could provide greater health benefits to the child.February 2001 Update