You know what makes me sick?

THE YEAR I was diagnosed with celiac disease, I wrote the following on a page of my journal: “Relafen, Famotidine/Pepcid, Lorazepam, Cyclobenzaprine, Vioxx, Vicodin, Soma, that steroid: forgot name, Celebrex, Valium, Prevacid.”

The analgesics were for arrows of pain shooting from the nape of my neck to my fingers. The stomach soothers were for a constant, low-level ache that doctors diagnosed as irritable bowel syndrome. The Valium was for, as one doctor explained, “a certain anxiety you seem to have about your body.” I kept the list in case a doctor might ask me what medicines I had taken.

None ever did, despite the fact that I spent many afternoons waiting in doctors’ offices hoping to learn why I felt so sick. Many times while I sat in the waiting rooms, young, blow-dried women carrying briefcases with poetic names of prescription drugs embossed on them bypassed me and went directly into the doctor’s office. I frequently returned home from my visits with jewelry-sized boxes of the same drugs. “Start with these free samples,” the doctors instructed me. “Try them for four days, and call if you want a refill.”

Later that year, my stomach pain reappeared in greater intensity. During the previous six years, I’d driven myself, screaming, to emergency rooms for treatment, and doctors had sent me home with samples of Prevacid and leaflets on irritable bowel syndrome. But my new doctor decided that my diet of Celebrex had caused an ulcer, so she abruptly took me off the drug and put me on a regimen of antibiotics. When this produced migraines, the doctor prescribed Ultram, which caused, as the side effects warned, dizziness, sleeplessness and anxiety. I was up for three consecutive nights until the doctor gave me Klonopin. It took me years to get off this soothingly addictive drug.

I never had an ulcer. I never had irritable bowel syndrome.

I have celiac disease. I was 30 years old before I knew this -- and I was lucky. About 97% of people with celiac are undiagnosed.

Jerome Groopman’s widely acclaimed book, “How Doctors Think,” opens with an episode similar to mine. Anne Dodge consults nearly 30 doctors for her increasingly debilitating gastrointestinal symptoms, which include nausea, vomiting and diarrhea. She is diagnosed with anorexia and irritable bowel syndrome. After 15 years -- and severely malnourished -- Dodge finds a doctor who does something different. He observes her manner and listens to her -- and diagnoses celiac disease. He saves her life. Groopman concludes that doctors must pay more attention to patient reports and resist the temptation to dismiss poorly understood complaints as psychosomatic.

Research shows that the medical profession is dangerously unaware of this serious disease that affects nearly one person in 100. Celiac is the most common hereditary autoimmune disorder. Although the primary symptoms are gastrointestinal, the disease, if untreated, can affect many of the body’s systems.

Sufferers frequently spend years going from doctor to doctor before finding one who performs the requisite exams, including blood tests and an endoscopy. During the long wait, our bones may weaken or our teeth corrode, as undiagnosed celiac is linked to osteoporosis and enamel decay. We may develop cancer, neurological problems or infertility, which are other complications of untreated celiac. And we may be prescribed medicines for diseases we don’t have.

From 1966 to 1995, U.S. researchers published less than 1% of the approximately 6,000 articles on celiac. Long after the early 1990s, when European epidemiologists discovered the high prevalence of the disease in Europe, American physicians continued to insist it was extremely rare in this country.

This is beginning to change. U.S. researchers increasingly report that celiac disease is as common here as in Europe. The National Institutes of Health has launched a drive to increase doctors’ awareness of the disorder. Celiac research centers are multiplying, and patient advocacy groups disseminate their studies to the public over the Internet, in newsletters and at conferences.

So why were Anne and I misdiagnosed with irritable bowel syndrome? Why does celiac continue to receive less attention than most other gastrointestinal disorders, such as irritable bowel syndrome and Crohn’s disease?

One answer may lie in the increasing ability of pharmaceutical companies to influence doctors. Marcia Angell, former editor in chief of the New England Journal of Medicine, details how drug companies have become marketing machines for their products in her recent book, “The Truth About Drug Companies.” Thousands of sales representatives visit doctors’ offices and hospitals to make their pitches and offer free wares. Drug companies send physicians to conferences at plush resorts to hear about their drugs. As the New York Times recently reported, some physicians received millions of dollars to prescribe anemia medicines for their cancer patients. Although doctors insist that they are immune to the industry’s blandishments, a study published in the Journal of the American Medical Assn. concluded that “physician-industry interactions [appear] to affect prescribing and professional behavior.”

Irritable bowel syndrome, for instance, has been the focus of a huge marketing campaign by drug companies for several years. Newspapers and TV ads seek to increase demand for new drugs by exaggerating both the problems the syndrome causes and the size of the affected population. Although one drug manufacturer asserted that the condition affects 20% of the population, researchers have concluded that the disease’s incidence is 5% and that most sufferers experience only mild symptoms.

No drugs exist to treat celiac. After a doctor sent me for an endoscopy, which produced the diagnosis, I began a gluten-free diet, eliminating wheat, barley and rye, which are found in most processed foods. The diet is annoying, expensive, occasionally dull, but ultimately liberating. I no longer append each meal with pills, no longer arrive at the doctor’s office with a list of side effects written on file cards, and, for the first time in my life, my stomach is mostly silent. My mouth sores have disappeared. My back pain has abated. My blood retains sufficient iron.

I am relieved that treatment for celiac is as low-tech as rice crackers. But I wonder whether, if my disease did have a pharmaceutical remedy, doctors would have diagnosed it earlier. “Here,” they would have said, “free samples! Take four.”