Gut check.

Most people don't think much about their lymph glands kidneys, blood cells, or lungs. But, when it comes to the digestive, system everyone's an expert,

Or are they?

Do you know, for example which of these statements are true and which are false?

* Heartburn can increase your risk of esophageal cancer.

* Ulcers are usually caused by stress and spicy foods.

* If left untreated, diverticulosis causes serious complications in most patients.

For the answers, see our top-to bottom speed course on the most common threats to your gastrointestinal tract.

Gut Check

You may be surprised to learn that:

* heartburn can increase your risk of esophageal cancer,

* stress or spicy foods do not cause ulcers, and

* diverticulosis usually has no complications.

It's not just the myth and misinformation surrounding the gut that may have led you astray. What we know about the GI tract is rapidly changing. Researchers now have a much better idea of what can and cannot protect your digestive tract. Whether you're trying to avoid an uncomfortable bout of indigestion or a life-threatening case of cancer, our guide can tell you what to eat, what drugs or tests to take, and what warning signals to watch out for. This month we cover the most common and potentially serious problems of the GI tract. In a future issue we'll tackle gas and some other short-term stomachaches.

Heartburn or Acid Reflux

Most people call it heartburn. Commercials call it acid reflux. If you have it often enough, doctors call it gastroesophageal reflux disease, or GERD. But it always feels the same: a burning sensation in your chest or throat.

"What people experience as acid indigestion or heartburn is stomach acid making its way up the lower esophagus," says Susan Taylor Mayne, a cancer researcher at Yale University.

In some people, for unknown reasons, the sphincter muscle that's supposed to keep acid in the stomach isn't tight enough, so the acid flows up into the esophagus. But the lining of the esophagus, unlike the stomach, can't withstand strong acids.

"The esophagus does fine with reflux over the short term," says Mayne. "But if it's a chronic problem for decades, you begin to see changes in the lining of the esophagus" (see "Esophageal Cancer").

The good news is that most people can avoid heartburn by changing what and when they eat or by taking drugs that curb stomach acid. "Inhibiting acid production may reduce the risk of cancer, but it's too early to know," says Mayne.

Symptoms: A burning sensation in the chest or throat and acid regurgitation. Some people have pain in the chest, hoarseness in the morning, difficulty swallowing, a dry cough, bad breath, or a feeling that food is stuck in their throat or that their throat is tight.

What to do: If you have symptoms at least once a week, see your doctor, who may recommend drugs that keep acid out of your esophagus (see "Dropping Acid," p. 4). But often, lifestyle changes can help:

* If you smoke, stop.

* Don't drink alcohol.

* Lose excess weight.

* Eat smaller meals.

* Wear loose-fitting clothes.

* Avoid lying down until at least three hours after a meal.

Some people claim that they're more likely to get heartburn after eating citrus fruits, chocolate, drinks with caffeine, fatty or fried foods, garlic, onions, mint flavorings, spicy foods, or tomato-based foods like spaghetti sauce, chili, and pizza.

But the evidence is sketchy, so don't swear off the entire list unless you're sure that it makes a difference in your symptoms.

Esophageal Cancer

Adenoma of the esophagus is not a good diagnosis. Only one out of eight people is alive five years after getting the news. (Four out of five victims are white men.) And the rate of new cases jumped four-fold between 1976 and 1994.

What causes adenoma of the esophagus? The best clue so far: chronic heartburn, or GERD.

"In people who have chronic reflux for decades, the cells lining the esophagus may undergo metaplasia--they start to look more and more abnormal," explains Yale's Susan Mayne. That condition, called Barrett's esophagus, occurs in 10 to 15 percent of people who have heartburn at least once a week.

People with Barrett's esophagus are 30 to 40 times more likely to get esophageal cancer than people without it. But only one out of 100 people with Barrett's gets esophageal adenocarcinoma each year. (The other major esophageal cancer, called squamous cell carcinoma, typically occurs in poorly nourished, heavy-drinking, low-income smokers, and it's on the decline.)

What's behind the jump in adenocarcinomas? The obesity epidemic may bear some of the blame, but researchers don't know how too much weight harms the esophagus.

"People assumed that obesity caused reflux because of overeating or because a high body mass could increase pressure on the stomach," says Mayne. "But recent studies don't support a clear link between obesity and reflux."

"Obesity may raise the risk by promoting growth factors or some other mechanism, as it does with other cancers," she adds.

Researchers have only a few other clues to go on. "We find a strong protective effect of fiber, as well as folate, vitamin C, and beta-carotene," Mayne notes. Those results are still preliminary, but they send a clear message. "The protective nutrients all show up in the same foods--fruits and vegetables." The fiber also shows up in whole grains.

A more troubling possibility: The rise in esophageal adenocarcinoma may be linked to the decline in stomach cancer.

"Because of better sanitation, the prevalence of Helicobacter in the U.S. is going down," Mayne explains.

Helicobacter pylori is a bacteria that takes up residence in the stomach. It causes most ulcers and raises the risk of stomach cancer. Doctors can treat it with antibiotics, but that may be bad news for the esophagus.

"When Helicobacter colonizes the stomach, it inhibits acid production," says Mayne. So wiping out the H. pylori may protect against one cancer while promoting another.

"That could explain why stomach cancer is dropping and esophageal cancer is rising, but it's still just a theory."

Symptoms: Difficult or painful swallowing; severe weight loss; pain in the throat or back, behind the breastbone, or between the shoulder blades; hoarseness or chronic cough; vomiting; coughing up blood.

What to do: To lower your risk of esophageal cancer, lose excess weight, don't smoke, and eat eight to ten servings of fruits and vegetables a day. (A serving is only half a cup, so that's not unrealistic.) See your doctor if you have heartburn once a week or more.

Ulcers

"The personality makeup of persons with stress-related peptic ulcer is typified by the hard-driving executive who pushes himself too hard and restrains his emotions," explained an article in a 1970 medical journal. For 100 years, stress, spicy foods, and excess stomach acid were considered the causes of stomach ulcers.

But in the early 1980s, Robin Warren, a pathologist at Royal Perth Hospital in Australia, and his young colleague, Barry Marshall, became convinced that a bacteria was to blame. They often found the bug--Helicobacter pylori--burrowed into the stomach lining of people with stomach ulcers or inflammation.

At the time, no one thought that bacteria could survive in the stomach's strong acids. So Marshall decided to prove it.

One day in July 1984, he drank a "foul-tasting brew" laced with H. pylori. About a week later, he woke up at 5 a.m. vomiting and in pain. Within a decade, researchers had agreed that H. pylori causes about 70 percent of ulcers.

And 90 percent of the ulcers caused by H. priori are cleared by triple antibiotic therapy. (Triple therapy is actually two antibiotics plus a drug that either suppresses acid secretion or coats the stomach.)

Ulcers that aren't cured by antibiotics are usually caused by irritation from aspirin, ibuprofen, Celebrex, Vioxx, or other NSAIDs (non-steroidal anti-inflammatory drugs) that people often take for arthritis.

About 20 percent of Americans under age 40--and half of those over 60--have H. pylori in their stomachs. But most infected people don't get ulcers, possibly because some people are more resistant or some strains of the bacteria are less harmful.

How does the bug get into your gut in the first place? "That's the $64,000 question," says Frank Hamilton, Chief of the Digestive Disease Program at the National Institute of Diabetes & Digestive & Kidney Diseases in Bethesda, Maryland.

Studies suggest that H. pylori can be spread by kissing (it's in saliva) or by what is delicately called the "fecal-oral route." "Many kids neglect to wash their hands after using the bathroom," Hamilton explains.

Symptoms: The most common symptom is a dull, gnawing ache in the abdomen that typically:

* comes and goes for several days or weeks,

* occurs two to three hours after a meal,

* occurs in the middle of the night (when the stomach is empty), and

* is relieved by taking antacids or eating.

Other symptoms include weight loss, poor appetite, bloating, burping, nausea, or vomiting, but some people have only mild symptoms.

What to do: See your doctor if you have symptoms of an ulcer. If you're under 45--and some experts say under 50 or 55--most doctors test for H. pylori (in your blood, breath, or stool) and prescribe triple antibiotic therapy if you've been exposed to the bug.

If you're older, the odds are that your physician will recommend an endoscopy (because older people are more likely to have a more serious problem). While you're sedated, the doctor slips a thin, lighted tube with a tiny camera down your throat.

Many doctors still do an upper GI series, which means they x-ray the esophagus, stomach, and upper small intestine after the patient drinks a chalky liquid that contains barium. But an endoscopy is a better way to diagnose either ulcers or cancer.

Stomach Cancer

Worldwide, the number of people who die of stomach cancer is second only to the number who die of lung cancer. In the U.S., stomach cancer kills only about 12,000 people a year. But when it strikes, it's deadly. Only one out of five people is alive five years after being diagnosed.

"There's been a decline in stomach cancer in Western countries since the 1940s," says Anna Wu of the University of Southern California in Los Angeles. "That's partly due to better refrigeration and an increased intake of fresh fruits and vegetables."

During the past 60 years, household refrigerators have replaced riskier means of preserving foods. "In Asian countries with a high risk of stomach cancer, many meats and vegetables are salted, which leads to the production of mutagens," she explains. "And some foods are actually moldy."

Salt not only sets the stage for mutagens to form, but may also act as an irritant in the stomach. Smoking doubles the risk of stomach cancer, while fruits and vegetables seem to protect the stomach. "Most studies have looked at vitamin C, but fruits and vegetables have a variety of phytochemicals that could also be protective," says Wu.

But the biggest risk factor is the bacterium H. pylori. "Worldwide, it accounts for an estimated 40 to 50 percent of the risk of stomach cancer," says Wu. "Estimates in the U.S. are lower because the prevalence of H. pylori is lower."

Why? "Transmission typically occurs in childhood, so it has declined as families become smaller and less crowded." Another factor: "The use of antibiotics to treat ear infections or other illnesses in children has also lowered rates."

That's not to say that H. pylori is rare in the U.S. "Experts estimate that 30 to 40 percent of Americans have H. pylori," says Wu. (It's closer to 70 or 80 percent in some countries.)

"H. pylori is a risk factor for stomach cancer, but by itself it's not sufficient to cause the disease," she explains. Otherwise, stomach cancer would be far more common.

So far, experts don't recommend that people without GI symptoms get tested for H. pylori. "There are no guidelines to screen everyone because we have no clinical trials showing that it would reduce the incidence of disease," says H. pylori expert Naoki Chiba of McMaster University in Hamilton, Canada.

Symptoms: Indigestion or a burning sensation (heartburn), discomfort or pain in the abdomen, nausea, vomiting, diarrhea, constipation, bloating after meals, loss of appetite, weakness, fatigue, blood in the stool or vomit.

What to do: An endoscopy is the best way to diagnose stomach cancer. But don't panic: Stomach or esophageal cancer is diagnosed in less than two percent of patients who undergo an endoscopy.

Diverticular Disease

If you're 60 to 80, the odds are one out of two that you've got diverticulosis. If you're over 80, you can pretty much count on it.

Diverticulosis means that small pouches in your colon bulge out like an inner tube that pokes through weak spots in a tire. When the pouches become infected or inflamed, it's called diverticulitis.

The good news: That happens in less than 10 percent of people with diverticulosis. Complications like bleeding, blockages, or tears in the colon are still less common.

Even better news: "Diverticulosis is largely preventable," says Ed Giovannucci of the Harvard School of Public Health.

Studies suggest that eating too little fiber makes stools hard. When muscles strain to move the stools, it raises pressure inside the colon, and that pressure could cause weak spots to bulge.

"We found that eating fiber was related to about a 40 percent reduced risk of diverticular disease," says Giovannucci. (His studies, of some 47,000 male health professionals, looked only at diverticular disease that was serious enough to cause symptoms.)

Researchers believe that exercise may also prevent diverticulosis, by speeding food through the gut.

"We found about a 40 percent lower risk of diverticular disease in physically active men," says Giovannucci. "And it was a relatively sedentary group, so the most active men weren't running marathons."

And when his research team looked at fiber and activity together, the impact was impressive. "People with low fiber intake and low physical activity had two and a half times the risk of people with high fiber intake and high activity."

Those findings should come as no surprise to anyone who knows the geography of diverticulosis. "It's a disease that's common in Western societies, but rare in populations that are active and eat more fiber," Giovannucci points out.

Symptoms: Diverticulosis may cause mild cramps, bloating, or constipation, but it usually has no symptoms. The most common sign of diverticulitis is tenderness or pain around the left side of the lower abdomen. Fever, nausea, vomiting, chills, cramping, and constipation can also occur.

What to do: Shoot for at least half an hour of exercise and 25 to 30 grams of fiber every day (see "The Roughage Report," p. 7).

Many doctors used to recommend avoiding foods like tomatoes or strawberries, because they believed that the small seeds could get stuck in the pouches and cause inflammation. There is no good evidence to support that advice.

Constipation

It's the most common gastrointestinal complaint in the U.S., accounting for roughly two million visits to the doctor each year.

Americans spend $ 725 million on laxatives annually. But they don't fix the underlying problem. For most people, that's the same lack of fiber and exercise that leads to diverticulosis.

"We found a strongly protective effect in women who ate the most fiber and had the highest level of activity," says Harvard's Ed Giovannucci.

Researchers have done few large studies on constipation, in part because the condition is difficult to define. Frequency is less important than whether bowel movements are hard or dry.

"But to study thousands of women, we had to pick a definition that was practical," explains Giovannucci. "So we looked at women who had two or fewer bowel movements a week."

Beyond fiber and exercise, he found that "moderate alcohol intake was beneficial. So was one or two cups of coffee a day. But four or five cups a day was associated with an increased risk of constipation."

Symptoms: Hard, dry, or difficult bowel movements, often accompanied by complaints of feeling bloated or sluggish.

What to do: Fiber makes stools bulkier and softer. Shoot for 25 to 30 grams a day from whole grains (especially wheat bran), beans, vegetables, and fruit (see "The Roughage Report"). Try for at least half an hour of exercise each day. And drink at least eight cups of liquids daily.

Colon Cancer

If you're a nonsmoker, the only cancer you're more likely to get than colon cancer is breast cancer (if you're a woman) or prostate cancer (if you're a man).

Unlike breast and prostate cancer, researchers know quite a bit about how to reduce the risk of colon cancer.

"The vast majority of colon cancers could be prevented," says Harvard's Ed Giovannucci. His research team has looked at middle-aged men who had the lowest risk of colon cancer.

"These men were doing at least moderate physical activity--about three hours a week--and they were not obese, though they weren't necessarily slim," he explains.

"The men ate red meat on average only once a week, they took a daily multivitamin with folic acid, they drank some alcohol--less than two drinks a day--and they hadn't smoked heavily when they were young."

The results were impressive. "If everyone fell into that low-risk group, we could prevent 70 percent of colon cancers," Giovannucci estimates.

One risk factor the study didn't look at: "Calcium is slightly protective," notes Giovannucci. "But in our other studies, the benefit maxed out at about 800 milligrams a day."

He cautions men to avoid either too much or too little calcium. "We see a clear association with an intake of more than 1,500 milligrams of calcium a day and an increased risk of prostate cancer," he says.

Giovannucci's study only looked at preventing colon cancer. Detecting it early--through the use of colonoscopy or sigmoidoscopy--could remove colon polyps before they turn into cancer.

Symptoms: Blood in the stool or rectal bleeding, a change in stool shape, a cramping pain in the lower stomach, an urge to visit the bathroom when you don't really need to go.

What to do: Exercise, lose excess weight, take a multivitamin-mineral with folic acid, limit red meat, and get enough calcium. (That's 1,000 mg a day if you're under 50 and 1,200 mg a day if you're 50 or older. If you're a man, don't get more than 1,500 mg a day.) If you're 50 or older, get a colonoscopy every ten years.

Dropping Acid

Whether it's heartburn, indigestion, or some other pain or discomfort in your upper gut, if you're like most people, you probably reach for an over-the-counter remedy. Just remember that if your symptoms last for two weeks or more--or if you have "alarm symptoms" like bleeding or weight loss--don't keep treating yourself (see "When to Worry").

"The intermittent use of a mild antacid is fine," says Naoki Chiba of McMaster University in Hamilton, Canada. "But otherwise, get yourself to a doctor."

Depending on your age, the symptoms' severity, and other factors, doctors may examine your esophagus and stomach with an endoscope. But in other cases, they may simply prescribe something stronger than what you can get from the drugstore shelf. Here's a rundown of which drugs do what and how.

* ANTACIDS. Over-the-counter antacids like Alka-Seltzer, Maalox, Mylanta, Pepto-Bismol, Rolaids, Riopan, and Tums use magnesium, calcium, or aluminum to neutralize the acid in your stomach. Magnesium salts can cause diarrhea and aluminum salts can cause constipation, so the two are often combined.

* H2 BLOCKERS. Pepcid (famotidine), Tagamet (cimetidine), Axid (nizatidine), and Zantac (ranitidine) make your stomach secrete less acid. They're available over the counter or in prescription strength.

H2 blockers work for about half of people with acid reflux. For some people, taking both an antacid and an H2 blocker at bedtime works best. The antacid first neutralizes the acid in the stomach, while the H2 blocker keeps the stomach from producing more acid. By the time the antacid stops working, the H2 blocker has kicked in.

* PROTON PUMP INHIBITORS. Prilosec (omeprazole), Prevacid (lansoprazole), Protonix (pantoprazole), Aciphex (rabeprazole), and Nexium (esomeprazole) are available by prescription only. They're more effective at reducing stomach acid than H2 blockers and relieve acid reflux symptoms in almost everyone.

* FOAMING AGENTS. Gaviscon and similar drugs reduce reflux by covering your stomach contents with foam. They may help if you have no damage to your esophagus.

* PROKINETICS. Prescription drugs like Urecholine (bethanechol) and Reglan (metoclopramide) strengthen the esophageal sphincter and make the stomach empty faster. Reglan has frequent side effects that limit its usefulness.

When to Worry

Some GI symptoms are serious enough to warrant an immediate call to your doctor. For example, black stools or vomit that looks like coffee grounds could be a sign of internal bleeding. A sudden, sharp pain could mean that an ulcer has burrowed through the wall of the stomach or small intestine. Indigestion and shortness of breath, sweating, or pain radiating to the jaw, neck, or arm could signal a heart attack.

See a doctor immediately if you have any of the following:

* weight loss or appetite loss,

* bloody or black tarry stools,

* persistent vomiting or vomit that's bloody or looks like coffee grounds,

* severe, sudden, or sharp pain in the abdomen,

* difficulty swallowing, or

* indigestion accompanied by shortness of breath, sweating, or pain radiating to the jaw, neck, or arm.

Helicobacter burrows in. H. pylori bacteria (pink) secrete enzymes that neutralize stomach acid long enough so they can burrow into the stomach's protective mucous layer (blue). Once that layer is weakened, both acid and the bacteria can irritate or eat through the stomach lining, which leads to a sore, or ulcer. If you have an ulcer (or its symptoms) and you test positive for H. pylori, antibiotics should get rid of it. But don't assume that antibiotics will take care of any chronic stomachache.

Ulcers account for only 15 to 25 percent of chronic stomach pain or discomfort, which doctors call dyspepsia. In 60 percent of patients, doctors find no ulcer. And "in most people who have no ulcer, treating H. pylori doesn't change the symptoms of dyspepsia," says Frank Hamilton of the National Institute of Diabetes & Digestive & Kidney Diseases. What's more, screening and treating everyone for H. pylori isn't harmless. It may spread resistant bacteria that could someday make antibiotics worthless.

The Roughage Report

People who eat more fiber have a lower risk of constipation and
diverticular disease. Here are some good (and not-so-good) sources.
Shoot for 25 to 30 grams a day.

                                               Fiber
                                              (grams)
Fruit

Figs, dried (2)                                   5
Apple (1) or blueberries (1 cup)                  4
Avocado (1/3)                                     3
Banana (1) or orange (1)                          3
Cherries (1 cup) or dried prunes (5)              3
Strawberries (7 cup)                              3
Apple, no skin (1)or grapes (1 1/2 cups)          2
Apricots, dried ( 1/4 cup)                        2
Nectarine or peach (1)                            2
Pineapple (1 cup)                                 2
Plums (2)                                         2
Cantaloupe or watermelon (1 cup)                  1
Grapefruit (1/2)                                  1
Apple juice or orange juice (1 cup)               0

Vegetables
(1/2 cup cooked, unless noted)

Baked potato, with skin (1)                       4
Green peas                                        4
Baked sweet potato, with skin (1)                 3
Brussels sprouts or carrots                       3
Broccoli, cabbage, cauliflower, or corn           2
Carrots, raw (1)                                  2
Green beans or spinach                            2
Asparagus                                         1
Celery (1 stalk)                                  1
Green pepper, raw (1/2)                           1
Iceberg or romaine lettuce (1 cup)                1
Tomato, raw (1/2)                                 1

Beans & Veggie Burgers
(1 cup cooked, unless noted)

Healthy Choice Hearty Chili Beef                  8
Lentils (1/2 cup)                                 8
Pinto beans (1/2 cup)                             7
Progresso Lentil Soup                             7
Chickpeas (1/2 cup)                               6
Healthy Choice Bean and Ham Soup                  6
Kidney beans (1/2 cup)                            6
Boca Burgers, Original (1)                        4
Healthy Choice Split Pea and
  Ham Soup                                        4
Campbell's Healthy Request Minestrone             3
Gardenburger, Original (1)                        3
Tofu (3 oz.)                                      0

Grains & Pasta (1 cup cooked, unless noted)

Bulgur                                            8
Barley or whole-wheat spaghetti                   6
Brown rice                                        4
Aunt Jemima Buckwheat Pancake
  Mix (4 4-in.)                                   3
Couscous, macaroni, or spaghetti                  2
White rice                                        1

Cereal (1 cup, unless noted)

General Mills Fiber One (1/2 cup)                14
Kellogg's All-Bran Bran Buds (1/3 cup)           14
Kellogg's All-Bran Extra Fiber (1/2 cup)         13
Kellogg's All-Bran Original (1/2 cup)            10
General Mills Multi-Bran Chex                     8
Kashi Good Friends (3/4 cup)                      8
Post Raisin Bran                                  8
Post Spoon Size Shredded Wheat,
  Original                                        6
General Mills WheatChex                           5
Post Bran Flakes (3/4 cup)                        5
Post Grape-Nuts (1/2 cup)                         5
Wheatena (cooked)                                 5
Kellogg's Complete Oat Bran (3/4 cup)             4
Quaker Oats (cooked)                              4
General Mills Cheerios or Wheaties                3
General Mills Whole Grain
  Total (3/4 cup)                                 3
Quaker 100% Natural Low Fat
  Granola (2/3 cup)                               3
Kellogg's Corn Flakes or Product 19               1
Kellogg's Special K or Rice Krispies              0

Bread (2 slices) & Crackers

Arnold, Brownberry, Oroweat, or
 Roman Meal 100% Whole Wheat                      6
Arnold or Oroweat Bran'nola Orig                  6
Wasa Hearty Rye Crispbread (3)                    6
Nabisco Triscuits (7)                             4
Pepperidge Farm 100%
  Stoneground Whole Wheat                         4
Wonder Stoneground 100%
  Whole Wheat                                     4
White bread                                       1

Chart compiled by Sarah Wade.

Sources: USDA National Nutrient Database for
Standard Reference and manufacturers.

Exit Strategy

Don't take any laxative for more than a week without checking with your., doctor. Also, see your physician if you get a skin rash (you could be allergic), and don't take a laxative within two hours of taking other medicine.

* BULK-FORMERS (like Metamucil, Citrucel, Konsyl, and Serutan) absorb water in the intestine and make the stool softer. They're the safest laxatives. Bran works the same way.

* STOOL SOFTENERS (like Colace, Dialose, and Surfak) keep the stool moist and prevent dehydration.

* SALINE LAXATIVES (like Milk of Magnesia, Citrate of Magnesia, and Haley's M-O) act like a sponge to draw water into the colon for easier passage of stool.

* LUBRICANTS (like mineral oil) grease the stool, which enables it to move through the intestine more easily. Lubricants impair the absorption of fat-soluble vitamins and can, in rare cases, cause pneumonia.

* STIMULANTS (like Correctol, Dulcolax, Purge, Feen-A-Mint, and Senokot) cause rhythmic muscle contractions in the intestines. They can lead to dependency, so they're only safe to take occasionally.