Inflammatory Diarrhea
What are three things that can often be seen in the stool of patients with inflammatory diarrhea?
What are mucus, blood, and leukocytes?
True or False?
Steatorrhea caused by malabsorption = Unabsorbed lactose remains in the intestinal lumen, drawing water in and producing acidic stool with gas and bloating.
What is True?
Carbohydrate malabsorption causes osmotic diarrhea via unabsorbed sugars and bacterial fermentation
A patient’s diarrhea improves with fasting. Which type of diarrhea is this, and why?
What is Osmotic diarrhea?
Explanation: Because unabsorbed solutes are no longer present without intake
Identify cells, cytokines, and chemokines that are involved in the immune response leading to inflammatory diarrhea.
What are: Macrophages, dendritic cells, and proinflammatory cytokines and chemokines (IL-6, IL-12, TNF-α, CXCL8)?
Process: Mucosal damage due to infection or IBD → Immune activation (cytokines) → Cell recruitment (neutrophils, lymphocytes) → Tissue destruction (ulcers, erosions) → Hypersecretion of water and electrolytes + impaired absorption → Bloody, mucoid diarrhea
True or False?
Steatorrhea caused by malabsorption = the failure to break down triglycerides due to a lack of pancreatic lipase or bile salts.
What is False?
This is fat maldigestion (defective digestion due to pancreatic enzyme or bile acid deficiency)
A patient with cholera has persistent diarrhea despite fasting. What is the molecular mechanism?
What is Secretory diarrhea?
Increased cAMP → CFTR activation → Cl- secretion → water follows into the lumen, making the diarrhea watery
Name at least three illnesses that can cause inflammatory diarrhea.
What are: IBD, colorectal cancer, and infections, including Shigellosis, nontyphoidal Salmonella, enteroinvasive/enterohemorrhagic E. coli, Campylobacteriosis, Yersiniosis, Amebiasis, and C. diff (rarely bloody)?
What is the structural defect in Celiac disease that causes malabsorption of fats?
What is Villous atrophy?
Villous atrophy leads to the inability of enterocytes to absorb lipids even when micelles are properly formed.
Compare stool osmotic gap findings in osmotic vs secretory diarrhea and explain the mechanism.
Stool osmotic gap = 290 − 2(Na⁺ + K⁺)