Helicobacter pylori (H. pylori) bacteria are a common cause of digestive illnesses, including gastritis (the irritation and inflammation of the stomach lining), peptic ulcers (sores in the lining of the stomach, small intestine, or esophagus), and even stomach cancer later in life. These bacteria are found worldwide, but especially in developing countries, where up to 10% of children and 80% of adults are likely to have had an H. pylori infection — usually without any symptoms. Signs and Symptoms Anyone can have an H. pylori infection without knowing it — most H. pylori infections are "silent" and cause no symptoms. When the bacteria do cause symptoms, they're usually either symptoms of gastritis or peptic ulcer disease. In kids, symptoms of gastritis may include nausea, vomiting, and abdominal pain, although these symptoms are seen in many childhood illnesses. H. pylori, which used to be called Campylobacter pylori, also can cause peptic ulcers (commonly known as stomach ulcers). In older kids and adults, the most common symptom of peptic ulcer disease is a gnawing or burning pain in the abdomen, usually in the area below the ribs and above the navel. This pain often gets worse on an empty stomach and improves as soon as the person eats food, drinks milk, or takes antacid medicine. Kids who have peptic ulcer disease can have ulcers that bleed, causing hematemesis (bloody vomit or vomit that looks like coffee grounds) or melena (stool that's black, bloody, or looks like tar). Younger children with peptic ulcers may not have such clear symptoms, so their illness may be harder to diagnose. Contagiousness Scientists suspect that H. pylori infection may be contagious because the infection seems to run in families and is more common where people live in crowded or unsanitary conditions. Although research suggests that infection is passed from person to person, exactly how this happens isn't really known. Diagnosis Doctors can make the diagnosis of an H. pylori infection by using many different types of tests. A doctor may: look at the stomach lining directly. The patient will be under sedation during this procedure, which involves inserting an endoscope — a small, flexible tube with a tiny camera on the end — down the throat and into the stomach and duodenum. The doctor may then take samples of the lining to be checked in the laboratory for microscopic signs of infection and for H. pylori bacteria. do blood tests, which can detect the presence of H. pylori antibodies. Blood tests are easy to do, although a positive test may indicate exposure to H. pylori in the past, not an active infection. do breath tests, which can detect carbon broken down by H. pylori after the patient drinks a solution. Breath tests are time-consuming, provide no information about the infection's severity, and can be difficult to perform in young children. do stool tests, which can detect the presence of H. pylori proteins in the stool (poop). Like breath testing, stool tests indicate the presence of H. pylori but give no information about an infection's severity. Treatment Doctors treat H. pylori infections using antibiotics. Because a single antibiotic may not kill the bacteria, your child will normally be given a combination of antibiotics. Usually, the doctor will also give antacids or acid-suppressing drugs to neutralize or block production of stomach acids. If your child has symptoms of bleeding from the stomach or small intestine, these symptoms will be treated in a hospital. Because H. pylori infection can be cured with antibiotics, the most important home treatment is to give your child any prescribed antibiotic medicine on schedule for as long as the doctor has directed. One way to help soothe the abdominal pain is by following a regular meal schedule. This means planning meals so that your child's stomach doesn't remain empty for long periods. Eating five or six smaller meals each day may be best, and your child should take some time to rest after each meal. It's also important to avoid giving your child aspirin, aspirin-containing medicines, ibuprofen, or anti-inflammatory drugs because these may irritate the stomach or cause stomach bleeding. With prolonged antibiotic therapy, H. pylori gastritis and peptic ulcer disease (especially ulcers in the duodenum, a portion of the small intestine) often can be cured. Prevention Right now, there's no vaccine against H. pylori. And because transmission isn't clearly understood, prevention guidelines aren't available. However, it's always important to make sure you and your family: Wash your hands thoroughly. Eat food that's been properly prepared. Drink water from a safe source. When to Call the Doctor Call your doctor immediately if your child has any of these symptoms: severe abdominal pain vomit that's bloody or looks like coffee grounds stool that's bloody, black, or looks like tar lasting gnawing or burning pain in the area below the ribs that improves after eating, drinking milk, or taking antacids However, it's important to remember kids can get stomachaches for many reasons — like indigestion, viruses, tension and worry, and appendicitis. Most stomachaches are not caused by H. pylori bacteria. Back to Articles Related Articles What Are Germs? You know they can hurt you, but what are these invisible creatures? Find out in this article for kids. Read More Germs: Bacteria, Viruses, Fungi, and Protozoa Germs are the microscopic bacteria, viruses, fungi, and protozoa that can cause disease. Read More Hand Washing: Why It's So Important Washing your hands well and often is the best way to keep from getting sick. 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