How does one make a diagnosis of celiac disease? Celiac disease is a common cause of chronic fatty diarrhea, but may present without diarrhea. The population prevalence in the United States is estimated to be just less than 1%. Serologic testing for immunoglobulin A (IgA) antibodies against tissue transglutaminase is the preferred noninvasive test, but …
How is chronic fatty diarrhea evaluated Chronic fatty diarrhea is due to either maldigestion or malabsorption. Maldigestion can occur with pancreatic exocrine insufficiency, with ingestion of the lipase inhibitor orlistat, or if there is a bile acid deficiency, which reduces fat emulsification. Malabsorption typically is due to mucosal diseases such as celiac disease, small intestinal …
What is the likely outcome in patients with chronic secretory diarrhea in whom a diagnosis cannot be reached? Diagnostic testing may fail to reveal a cause for chronic diarrhea in up to 25% of patients with chronic diarrhea depending on referral bias and the extent of evaluation. Some patients with chronic secretory diarrhea that evades …
What is Bayes theorem? How does it relate to the diagnosis of peptide-secreting tumors? Bayes theorem links the prevalence of the diagnosis to the positive predictive value of a diagnostic test. The positive predictive value of a test depends on the likelihood of the condition in the population to be tested, not only on the …
When should neuroendocrine tumors be suspected as a cause of chronic secretory diarrhea? Neuroendocrine tumors are uncommon causes of chronic secretory diarrhea. For example, one VIPoma might be expected per 10 million people per year. The below table lists these tumors and their markers. Because of the rarity of these tumors as a cause for …
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Evaluation of chronic secretory diarrhea Because there are many causes of chronic secretory diarrhea, an extensive evaluation is necessary. Rare cases of infection should be excluded by bacterial culture and examination of stool for parasites or tests for protozoal antigens. Stimulant laxative abuse is best excluded by looking for laxatives in the urine or stool. …
How to evaluate osmotic diarrhea? Osmotic diarrheas are typically due to ingestion of poorly absorbed cations, such as magnesium, or anions, such as sulfate. In addition, carbohydrate malabsorption, such as that caused by ingestion of lactose in a patient with lactase deficiency, and ingestion of poorly absorbable sugar alcohols, such as sorbitol, can lead to …