Pathophysiology
- Increased active anion secretion
- Decreased absorption of H2O and lytes
- Inhibited or defective absorption
- Luminal presence of osmotically active agents
- Increased propulsive motor activity causing decreased contact time
- Decreased absorptive surface area
History
- Etiology: travel, homosexual contact, outbreaks, foods ingested, extraintestinal manifestations of IBD, antibiotics, steatorrhea, weight loss, immunosppressed, laxative use, malignancy history
- Manifestation of mucosal inflammation: fever, blood in stool, abdo pain between BM, tenesmus
- Severity: frequency, duration
Physical exam
- General appearance
- Vitals
- Volume status
- Abdominal exam
- Rectal exam
Investigations
- Stool WBC
- Culture/sensitivity
- O&P
- Flexible sigmoidoscopy
- C.difficile toxin
Differential diagnosis
- Infectious
- Viral (i.e. Norwalk, Rotavirus)
- Bacterial Infectious, Bacterial Toxic
- Giardia
- Food poisoning (Salmonella, spont resolution within 24-48 hr)
- Traveller’s (E. coli, use bismuth subsalicylate, empiric quinolone)
- Drugs: laxatives, antacids, antibiotics can cause acute and chronic diarrhea. Pseudo-membranous colitis 2° to Clostridium difficile
- Functional/Irritable colon
- Impaction
- Malabsorption: lactose intolerance, celiac disease, pancreatic insufficiency, immunodeficiency
- Inflammatory Bowel Disease
- Endocrine: diabetes, hyperthyroidism
- Tumor: partial obstruction or secretions
- Immune Deficiency
Treatment
- Replace electrolyte and fluids
- Antimotility agents: loperamide (contraindicated in mucosal inflammation)
- Absorbants: Kaopectate (absorb intestinal toxins/micro-organisms, and by coating intestinal mucosa)
- Bismuth subsalicylate
- Antibiotics
Chronic diarrhea
- Inflammatory: Ulcerative colitis, Crohn’s, malignancy: lymphoma, adenocarcinoma (fever, hematochezia, pain, weight loss)
- Osmotic: ingestion, lactose intolerance, medications, laxatives (decreased stool volume with fasting)
- Maldigestion/malabsorption: pancreatic insufficiency, bile salt deficiency, celiac sprue, Whipple’s disease, bowel resection (decreased stool volume with fasting)
- Secretory: bacterial enterotoxins, secretagogues, VIP, gastrin, carcinoid
- Functional
Stool osmotic gap = OSMstool(usually 290) – [2 x (Nastool + Kstool)]
- increased in osmotic diarrhea (>50) and secretory diarrhes (<50)
Vitamin K dependent clotting factors: 2, 7, 9, 10, protein C, protein S (TNTS)