Pathophysiology of Diarrhea & Malabsorption Flashcards
Sudden-onset diarrhea with abdominal cramps and fever point to what cause?
Infectious
How is lactose intolerance diagnosed?
Clinically - confirmed by a hydrogen breath test or lactose tolerance test
True/False. Patients with chronic diarrhea always require medical evaluation.
True
This type of diarrhea generally improves with fasting.
Malabsorptive diarrhea
What are the different mechanisms of diarrhea?
Osmotic, secretory, malabsorptive, exudative
True/False. Acute diarrhea lasts less than 7 days.
False - acute diarrhea lasts less than 14 days
What HLA are associated with Celiac disease?
HLA-DQ2 & HLA-DQ8
This mechanism of diarrhea is due to the retention of unabsorbable solutes in the gut.
Osmotic diarrhea
What is the clinical presentation of abetalipoproteinemia?
During infancy - failure to thrive, malabsorption, fat-soluble vitamin deficiency, steatorrhea
Tropical sprue is an enteropathy associated with tropical areas. What is the treatment?
Folic acid, tetracycline
Lactose intolerance produces what type of diarrhea?
Osmotic diarrhea
Patients with Celiac disease are at an increased risk of developing what cancers?
T-cell lymphoma, small bowel adenocarcinoma, esophageal cancer
Dermatitis herpetiformis is most associated with what disorder?
Celiac disease
Antibiotics are rarely given in cases of acute diarrhea, unless there is compelling evidence to suggest infectious origin. What is the primary focus for treatment of acute diarrhea?
Volume repletion
What are the most common bacterial causes of diarrhea in the USA?
Salmonella, Campylobacter, Shigella, STEC
What is the most common clinical presentation of malabsorption?
Steatorrhea
What is the most common cause of chronic diarrhea?
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion. What symptoms characterize the disorder?
Chronic, relapsing abdominal pain, changes in bowel habits (constipation or diarrhea), and abdominal bloating
Malabsorption syndrome occurs due to a disturbance in at least one of the four phases of nutrient absorption. What are the four phases?
Intraluminal digestion, membrane digestion, transepithelial transport, lymphatic transport
Blood-stained stools generally point to what cause of diarrhea?
Inflammatory
What characteristic is a hallmark of malabsorptive-related diarrhea?
Steatorrhea
How does dysmotility cause diarrhea?
Increases the transit time and reduced contact time of stool with surface mucosa for absorption
What is the treatment for Celiac disease?
Gluten-free diet
This mechanism of diarrhea is due to the excessive secretion of electrolytes and water into the gut, with decreased fluid absorption.
Secretory diarrhea
Mutations of the microsomal triglyceride transfer protein (MTTP) are associated with what disorder?
Abetalipoproteinemia
This mechanism of diarrhea is due to mucosal inflammation or ulceration with destruction of enterocytes and passage of purulent, bloody stool.
Exudative diarrhea
When does IBS most commonly present?
Teens and 20s
Bile acid diarrhea occurs due to a failure to reabsorb bile acids. Where does this reabsorption take place?
Terminal ileum
Pale stools that float are associated with what cause?
Malabsorption with steatorrhea
What non-pharmacological treatment is recommended for IBS?
Regular physical activity, diet high in fiber
What drugs may be used to treat IBS?
Anticholinergics, serotonin modulators and agonists, loperamide, TCAs
What histopathology findings are associated with Celiac disease?
Villous atrophy, cuboidal enterocytes, crypt hyperplasia, plasma cells
What is the common clinical presentation of Whipple’s Disease?
Diarrhea, malabsorption, weight loss in a man of 30-40yo
How long must diarrhea persist to be classified as chronic?
More than 30 days
What are potential complications of diarrhea?
Dehydration, hypovolemic shock, electrolyte imbalances, malabsorption, metabolic acidosis, hypokalemia
How does diarrhea due to disease of the small and large intestines differ?
Small intestine disease - Voluminous stools that are watery or fatty, bloating, mid-abdominal pain
Large intestine disease - Small-volume, frequent stools that may be bloody or mucoid, lower abdominal pain
What is the treatment for Whipple’s Disease?
Streptomycin or Penicillin & ceftriaxone, followed by one year of trimethoprim/sulfamethoxazole
What are the general causes of chronic diarrhea?
Diseases of the small intestine and colon, malabsorption, IBD
What is the gold standard for diagnosis of celiac disease?
Duodenal biopsy
What is the most sensitive test for diagnosis of Celiac disease?
IgA antibodies against tissue transglutaminase
Inflammatory bowel disease causes what type of diarrhea?
Exudative diarrhea
Enterocytes laden with lipid-filled vacuoles and acanthocytes are diagnositc of what disorder?
Abetalipoproteinemia
