In order to reach a diagnosis for digestive and liver problems, a thorough and accurate medical history must be taken by the doctor. Some patients need to undergo a more extensive diagnostic evaluation, which may include laboratory tests, imaging tests, or endoscopic procedures. These tests may include any, or all, of the following: Laboratory tests Albumin level - Below-normal levels of albumin, a protein made by the liver, found in the bloodstream are associated with many chronic liver disorders. Bilirubin level - This is produced by the liver and is excreted in the bile. Elevated levels of bilirubin may indicate an obstruction of bile flow or a defect in the processing of bile by the liver Complete blood count (CBC) - The different types of cells in the bloodstream are examined. White blood cells multiply when infection is present. Red blood cells will be present in smaller amounts than normal if blood has been lost, if the diet has been inadequate, or with certain diseases. Electrolyte test -These minerals are important for the body to function properly. Children who have lost large amounts of fluid due to vomiting or diarrhea often lose large amounts of the various electrolytes as well. Fecal fat test -The amount of fat contained in your child's stool is measured. If the digestive tract is working properly, only small amounts of fat will be present in the stool; the rest of the fat that was in the diet will have been digested and reabsorbed by the body. Fecal occult blood test - checks for hidden (occult) blood in the stool. It involves placing a very small amount of stool on a special card, which is then tested in the doctor's office or sent to a laboratory. Hydrogen breath test - This test measures the amount of hydrogen in the breath, and helps diagnose several digestive problems, including carbohydrate intolerance, bacterial overgrowth of the small intestine, and rapid transit of food through the small intestine Bacteria in the lower small intestine digest the rest of the carbohydrates, and produce hydrogen gas in the process. If carbohydrates are largely undigested by the time they reach the small intestine, bacteria will complete the digestive process; however, hydrogen gas being produced will cause cramps and bloating. This can happen if the carbohydrates are not digested properly. The child is told to fast overnight, and then breath samples are obtained by having the child blow into a balloon periodically. The amount of hydrogen produced in the breath will be measured at the start of the test, and at intervals after carbohydrates are given. Lactose tolerance test - This test helps determine if a child has trouble digesting lactose properly. If lactose is digested normally, blood glucose rises. If lactose is not digested as it should be, then the blood glucose level does not change throughout the test. Liver enzymes - Elevated levels of liver enzymes can alert doctors to liver damage or injury, since the enzymes leak from the liver into the bloodstream under these circumstances. Prothrombin time (PT) test - This test measures the time it takes for blood to clot. Blood clotting requires vitamin K and a protein made by the liver. Liver cell damage and bile flow obstruction can both interfere with proper blood clotting. Stool Culture - A stool culture checks for the presence of abnormal bacteria in the digestive tract that may cause diarrhea and other problems. A stool sample is collected and sent to a laboratory. In two or three days, the test will show whether abnormal bacteria are present. Urea breath test - This test helps diagnose the presence of Helicobacter pylori (H. pylori) in the digestive tract. If H. pylori is present in the stomach, then the urea will be converted into nitrogen and carbon. Imaging tests Computer tomography scan (CT or CAT scan) - A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. Lower GI (gastrointestinal) series (also called barium enema)- A procedure that examines the rectum, the large intestine, and the lower part of the small intestine. A fluid called barium is given into the rectum as an enema. An X-ray of the abdomen shows strictures, obstructions, and other problems. Magnetic resonance imaging (MRI) - A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. Metal objects cannot be present in the MRI room,All jewelry must be removed before the procedure. Magnetic resonance cholangiopancreatography (MRCP) - A special type of magnetic resonance imaging (MRI) that uses radio waves and magnets to obtain pictures of the bile ducts and internal organs. Oropharyngeal motility (swallowing) study - Your are given small amounts of a liquid containing barium to drink. It will shows up well on X-ray. A series of X-rays are taken to evaluate what happens as you swallows the liquid. This procedure is also called a modified barium swallow. Ultrasound - A diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels Upper GI (gastrointestinal) series - A diagnostic test that examines the organs of the upper part of the digestive system: the esophagus, stomach, and duodenum. A fluid called barium is swallowed. X-rays are then taken to evaluate the digestive organs. Endoscopic procedures Colonoscopy - a procedure that allows the doctor to view the entire length of the large intestine, and can often help identify abnormal growths, inflamed tissue, ulcers, and bleeding. It involves inserting a colonoscope, a long, flexible lighted tube, in through the rectum up into the colon. Endoscopic retrograde cholangiopancreatography (ERCP) - a procedure that allows the doctor to diagnose and treat problems in the liver, gallbladder, bile ducts, and pancreas. The doctor can examine the inside of these organs and detect any abnormalities Esophagogastroduodenoscopy (EGD) (also called upper endoscopy) - a procedure that allows the doctor to look at the inside of the esophagus, stomach, and duodenum. This allows the doctor to view the inside of this area of the body, as well as to insert instruments through a scope for the removal of a sample of tissue for biopsy. Other procedures Anorectal manometry - This test helps determine the strength of the muscles in the rectum and anus. Esophageal manometry - This test helps determine the strength of the muscles in the esophagus. It is useful in evaluating gastroesophageal reflux and swallowing abnormalities Esophageal pH monitoring - An esophageal pH monitor measures the acidity inside of the esophagus. It is helpful in evaluating gastroesophageal reflux disease (GERD). Magnetic resonance cholangiopancreatography (MRCP) - This uses magnetic resonance imaging (MRI) to obtain pictures of the bile ducts. The machine uses radio waves and magnets to scan internal organs and tissues. Capsule endoscopy - This helps doctors examine the small intestine, because traditional procedures, such as an upper endoscopy or colonoscopy, cannot reach this part of the bowel. This procedure is helpful in identifying causes of bleeding, detecting polyps, inflammatory bowel disease, ulcers, and tumors of the small intestine. Liver biopsy - A liver biopsy helps diagnose liver diseases. A small sample of liver tissue is obtained with a special biopsy needle and examined for abnormalities.