Anorexia nervosa, bulimia - medical causes of eating disorders - symptoms, treatment, diagnosis
Medical Tests


Defining the Terminology | Diagnostic Criteria | The Author Tells His Story | More Misdiagnosis Cases | A Quick Overview of the Genesis of Anorexia Nervosa | Medical Disorders And Conditions That Can Cause Anorexia, Weight Loss, Or Vomiting | Medical Tests | Diagnostic Deficiencies | A Message To Parents | A Message to Physicians | A Message to Therapists | A Quick Lesson on Human Nature | A Skeptical Look at the Conventional Wisdom | Public Awareness Campaigns Backfire | Depression and Anorexia | Classical Conditioning and Anorexia | Obsessive Compulsive Disorder | Excessive Exercise | Perfectionism | Sexual Abuse and Anorexia | Laxative Abuse | Bulimia Nervosa | Starvation Response | Malabsorption and Weight Loss | Body Mass Index : A Flawed Concept? | The Anorexic Voice | Art Therapy | Pro-Anorexia Web Sites | Celebrity Role Models | How Belief Skews Perception | Vegetarianism and Anorexia | Disturbing Trends in Medicine | Eating Disorder Clinics - Medical Testing | Frequently Asked Questions | About the Author | Contact Us | Bibliography | Disclaimer | The Future of Eating Disorders


If you have been diagnosed with Anorexia Nervosa, then your attending physician must have ruled out any medical conditions that could cause a loss of appetite or weight loss (even if a patient adheres rigidly to their mealplan, they may fail to gain weight due to malabsorption or metabolic disorders -  it is not uncommon for therapists to assume that the failure to gain weight is due to exercise or purging). A blood test will not reveal most of these conditions, although some elements may hint at certain disorders  (many physicians will dismiss these as resulting from malnutrition). There are a myriad of medical conditions that can cause loss of appetite (anorexia) or weight loss, including gastritis, stomach ulcer, duodenal ulcer, gallstones, acalculous cholecystitis, chronic inflamation, diabetes, tumors, chronic appendicitis, Chron's disease, addison's disease, etc. These chronic conditions can exist without the knowledge of the person afflicted by them, and make it very difficult to eat some foods. Some conditions will also cause malabsorption, which may prevent you from gaining weight.

Most physicians, psychotherapists, and eating disorder counsellors don't realize that all of the behaviors associated with AN can be triggered in certain individuals by these chronic conditions. Most of these disorders cause gastrointestinal distress (bloating, nausea, abdominal pain) when certain foods are consumed, causing a subconcious fear response in some sensitive individuals. This fear response can lead to an aversion to many foods, especially fatty foods and high calorie foods. Often this food aversion is misinterpreted as a "fat phobia" and merely reinforces the therapist's belief that you have AN. Some disorders will cause early satiety, making you feel full after only a few mouthfuls of food. Every person is unique, and the same condition may cause slightly different symptoms in different people (i.e. some people with gallstones experience no adverse symptoms, others suffer terribly).

What tests should be done by the medical team? Here's a list of the bare minimum. Some may not be suitable for a person that is severely malnourished, and the appropriateness of these test should be determined by your physician.

Diagnostic Tests

1. Blood Tests: These should include CBC, CBC with differential, blood chemistry, thyroid hormone, and Oral Glucose Tolerance Test. These tests can aid in the diagnosis of many medical disorders. Any abnormality should not be assumed to be due simply to malnutrition, as the underlying cause of the eating problem may be missed. Liver function tests can help diagnose biliary tract disorders. The Oral Glucose Tolerance Test can help in diagnosing hypoglycemia, which may play a role in bingeing and purging behavior associated with Bulimia Nervosa.

2. Urinalysis: Urinalysis comprises a battery of chemical and microscopic tests that help to screen for urinary tract infections, renal disease, and diseases of other organs that result in abnormal metabolites (break-down products) appearing in the urine

3. Upper GI Series:  The upper gastrointestinal (GI) series uses x-rays to diagnose problems in the esophagus, stomach, and duodenum (first part of the small intestine). It may also be used to examine the small intestine. The upper GI series can show a blockage, abnormal growth, ulcer, or a problem with the way an organ is working. During the procedure, the patient will drink barium, a thick, white, milkshake-like liquid. Barium coats the inside lining of the esophagus, stomach, and duodenum and makes them show up more clearly on x rays. The radiologist can also see ulcers, scar tissue, abnormal growths, hernias, or areas where something is blocking the normal path of food through the digestive system. Any abnormalities seen in this study may necessitate further studies such as gastroscopy or colonoscopy.

4. Oral Cholecystogram : This is a test to determine how the gall bladder is working.  Located under your liver, the gall bladder secretes bile to help with digestion.  Gallstones or other problems can keep the organ from working correctly.  To pinpoint the problem, patients are instructed to take several tablets the day before the examination and follow a special diet for 24 hours.  On the day of the examination, the radiologist will look at the gallbladder with X-rays to see if it takes up the special X-ray contrast contained in the tablets.  The exam itself is quick and painless.

5. Abdominal Ultrasound: Ultrasound (US) imaging, also called ultrasound scanning or sonography, is a method of obtaining images from inside the human body through the use of high frequency sound waves. The soundwaves' echoes are recorded and displayed as a real-time, visual image. An abdominal ultrasound image is a useful way of examining internal organs, including the liver, gallbladder, spleen, pancreas, kidneys and bladder. Particular attention should be paid to the gallbladder to look for gallstones or gallbladder wall thickening.  Note: this quick, noninvasive test clearly identified the cause of our daughter's anorexia (gallstones and cholecystitis).

6.CCK Cholesystogram (if the ultrasound is negative):The cholecystokinin stimulation test [CCK] measures the function of the gallbladder, not whether it contains stones. This test should be conducted in the erect position, not the normal supine position. The erect position most closely simulates the conditions of normal digestion. Gravity has a significant effect on digestion and in some individuals, and the gallbladder ejection fraction may vary from the supine to the erect position (refer to diagnostic deficiencies page).

7. Abdominal Flat Plate X-ray:  Abdominal X-rays can help diagnose a wide variety of problems including abnormal masses, enlarged organs, gallstones, bowel perforation or obstruction (this test is what raised my suspicions of disease in my daughter's case, since the x-ray showed fecal impaction).

8. Stool Samples:  Stool analysis can help diagnose malabsorption syndromes or parasitic infections. The presence of undigested food fragments suggests either extreme hypermotility or intestinal short circuits (eg, gastrocolic fistula). Greasy stools from a jaundiced patient can point to biliary tract disorders. Microscopic examination showing fat globules and undigested meat fiber suggests pancreatic insufficiency. Microscopy permits identification of ova or parasites.

The presence of fat in the stool (as much as 60 g/day) may be caused by any number of defects. Maldigestion may result when there is a lack of pancreatic lipase, which may occur in pancreatitis, cystic fibrosis, pancreatic cancer, or after gastric or pancreatic resection. An insufficient production of bile acids or an obstruction to bile flow will result in decreased fat absorption since bile acids are necessary for emulsification of fats into micelles for absorption. Malabsorption may result from ileal disease or resection, decreasing the area available for absorption of bile acids and fat and limiting the bile salt pool.

It is not uncommon for patients to be diagnosed with AN after recovering from a viral or parasitic infection, and the possibility of chronic infection should be considered in these cases. Once a condition has moved from acute to chronic, there may be alternating periods of constipation and diarrhea, abdominal distention and bloating, intestinal cramping followed by burning sensations and the sudden urge to eliminate. Generally, there is malabsorption of nutrients, especially fatty foods. Irritable bowel syndrome, blood sugar fluctuations, sudden food cravings, and extreme emaciation or overweight are all possible symptoms.

Testing for occult blood (stool guaiac test) can aid in the diagnosis of Crohn's disease, ulcerative colitis, gastritis, gastric ulcer, gastric carcinoma, esophageal varices, ateriovenous malformation, esophagitis, hiatal hernia, duodenal ulcer,intestinal polyps or diverticula.

A Note to Physicians:  Your Input is Needed! What other tests do you feel would be useful in diagnosing digestive disorders that may be making it difficult for the patient to eat?  Do you think these test are excessive or should there be more? Contact us and let us know!