Chronic Diarrhea

Chronic Diarrhea

1. TX

   • ●Loperamide (Immodium) ●Diphenoxylate with atropine (Lomotil)? ●Codeine ●Clonidine- inhibits electrolyte secretion ●Octreotide- for secretory diarrheas ●Bile salt binders-intestinal resection or ileal disease

2. CAUSES

   • MEDICATIONS
     • ●SE (not C diff) ●ABX, cholinesterase inhibitors, SSRIs, ARBs, PPIs, NSAIDs, metformin, allopurinol, & orlistat
   • OSMOTIC
     • ●Stool osmolality usually = serum (290mosm/kg) ●Osmotic Gap ➧↑ stool osmolality caused by ingestion or malabsorption of osmotically active substance ●Will resolve during fasting- dx w/ elimination trial for 2-3 wks
     • Common causes
       • ●Carb. malabsorption ●Lactose, fructose, sorbitol, ETOH ➧Retained carbs. cause abd. distention, bloating & flatulence d/t inadequate absorption ➧Hydrogen breath test or elimination trial ●Laxative abuse ●Malabsorption syndromes
   • FACTITIOUS DIARRHEA
     • ●Type of osmotic ●Laxative abuse or dilution of stool ●Chronic enigmatic diarrhea ➧15%=unemployed medical workers ●Dx of exclusion
   • SECRETORY DIARRHEA
     • ●↑ intestinal secretion or ↓ absorption ●High vol. watery w/ normal osmotic gap ●Does not Δ w/ fasting ●Dehydration & electrolyte imbalance common
     • Causes
       • ●Endocrine tumor ●Bile salt malabsorption ●Microscopic colitis ➧Older adults
   • INFLAMMATORY DIARRHEA
     • ●Present in most cases of ulcerative colitis & Crohns dz ●Abd.l pain, fever, weight loss, & hematochezia are not uncommon ●Microscopic colitis common in elderly
     • IBD
       • IBS VS IBD
         • IBD
           • ●Inflammatory bowel disease ●Dz=destructive ●Inflammation, permanent harm to intestines ●Umbrella term for chronic inflammatory d/o's (Crohn’s & Ulcerative Colitis) ●Can be seen on imaging ●Increased risk for colon cancer
         • IBS
           • ●Irritable bowel syndrome ●Syndrome= (group of sxs), Functional GI d/o (disturbance in bowel function w/out organic dz) ●No inflammation, rarely needs hospitalization or surgery ●Imaging not helpful ●No risk for colon cancer or IBD
       • Crohn's DZ
         • ●Unknown cause, w/ environmental & genetic contributors ●Starts in teens/young adults ●Entire GI tract ●Healthy areas interspersed ●Affects all layers of bowel walls
         • SX
           • ●Abd. pain ●Blood/mucous ●Weight loss ●N/V/D ●Mouth sores
       • Ulcerative Colitis
         • ●Unknown cause, w/ environmental & genetic contributors ●Starts in teens/young adults ●Limited to colon ●Continuous inflamm. ●Only affects inner most lining of colon
         • SX
           • ●Diarrhea ●Abd. pain ●Blood ●Weight loss ●Tenesmus/urgency ●Nocturnal stools
       • DX
         • ●Colonoscopy w/ Bx ●CT ●Barium enema ➧“lead Pipe Signs= UC ●Endoscopy ●Labs & stool studies ●Fecal leuks ●Screening: colonscopy w/n 8 yrs of dx to screen for colon cancer
       • TX
         • ●Cant be cured, manage sx is the goal via ↓ inflamm. (slows dz progression) ●Diet triggers: high fiber, uncooked produce, dairy, fatty/greasy foods ●Biologics (live antibiodies) ●Innumomodulators (↓ inflammatory response)-time delay, so often used w/ steroids ●Surgery
   • MALABSORPTION
     • ●Small intestinal mucosal conditions ●Intestinal resections ●Lymphatic obstruction ●Bacterial overgrowth ●Pancreatic insufficiency
     • SX
       • ●WEIGHT LOSS, osmotic diarrhea, steatorrhea, nutritional deficiency ●Significant chronic diarrhea w/o weight loss→unlikely to be malabsorption
   • MOTILITY D/O
     • ●IBS MC ●Stasis (ileus) or rapid transit of intestinal contents ➧Stasis results in bacterial overgrowth & malabsorption ●Systemic d/o or some surgeries can result in ↑ motility or ↓ transit time
       • IBS
         • ●Often assoc. w/ other functional d/o including fibromyalgia, chronic fatigue syndrome, anxiety, chronic pelvic pain, or TMJ ●F>>M ●Often begins in late adolescence or early adult, often during emotional stress ●Strong assoc. w/ sexual/emotional abuse
         • SX
           • ●Assoc. w/ large meals or stress ●May be relieved w/ BM ●Chronic abd. pain ●Constipation alternating w/ diarrhea ●Mucous in stool ●Gas, bloating, sensation of fullness ●Distention ●BM urge, w/o able to produce BM ●Nausea ●Does NOT occur at night
         • DX
           • ●Dx of exclusion ●Cannot be confirmed w/ imaging or labs ●Criteria: (Rome IV Criteria) ➧Abd. pain/discomfort for at least 1 day/wk for the last 3 months ➧W/ at least 2 of the following: ➧Sxs related to BM ➧Onset assoc. w/ Δ in freq. ➧Onset assoc. w/ Δ in form
         • TX
           • ●Exam= mild tenderness? ●Sx relief ●Pt edu. (dietary Δs, stress ↓, ↑ physical activity, etc) ●Cognitive behavioral therapy, stress management, relaxation training, Even acupuncture, gut directed hypnotherapy have shown promise ●Rx= symptoms
   • CHRONIC INFX
     • ●Parasites (giardia, E. hystolytica, Cyclospora, nematodes) ●Immunocompromise (cryptosporidium, CMV, Mycobacterium avium complex, Cyclospora
   • SYSTEMIC DISORDERS
     • ●Altered motility or absorption: ●Hyperthyroidism ●Diabetes ●Collagen vascular diseases
   • PSYCHOGENIC
     • ●Stress & anxiety ●Anxiety related conditions: OCD, PTSD, etc ●Sympathetic nervous system ●Fight or flight ●Slows stomach movements, while speeding up peristalsis in the large intestines→diarrhea

3. DX

   • Imaging
     • ●Plain films may show calcifications in the pancreas (chronic pancreatitis). ●CT better ●Upper GI w/ small bowel follow through, CT or MRI useful for: ➧Crohn’s dz ➧Small bowel lymphoma ➧Carcinoid & jejunal diverticula
   • Stool Testing
     • ●Fecal occult blood ●Fecal electrolytes (for osmotic gap) ●Fecal leukocytes or lactoferrin ➧Implies inflammatory diarrhea ●Qualitative staining for fat (malabsorption)➧ Sudan stain ●Stool for ova and parasites ➧Giardia or E. histolytica can be detected in wet mounts or w/ ELISA tests ➧Modified acid fast stains for cryptosporidium & cylospora ●Molecular panels for pathogens ➧Usually resulted in 5 hrs or so
       • ●24 hour stool collection for weight and quantitative fecal fat. >300g/24hrs confirms diarrhea 1-1.5g suggests secretory cause fecal fat >10g/24hrs indicates malabsorption Stool osmolality Stool pH <5.6 indicates carbohydrate malabsorption ●Stool osmolality less than serum indicates factitious diarrhea (something added to the stool- water or urine)
   • Labs
     • ●CBC ➧Anemia in malabsorption syndromes (folate, iron deficiency, or vitamin B12) & inflammatory conditions ●Chem 7➧Hypoalbuminemia is present in malabsorption, protein-losing enteropathies, and inflammatory diseases. ➧Hyponatremia and nonanion gap metabolic acidosis occur in secretory diarrheas. ●LFT ●Ca ●Phosphate & Albumin ●TSH ●Vitamin levels ●ESR/CRP: suggests inflammatory bowel disease. ●IgA tissue Transglutaminase (IgA tTG)➧ celiac
   • ●Endoscopic exam and mucosal biopsy for chronic persistent diarrhea Colonoscopy or sigmoidoscopy Inflammatory bowel disease Upper endoscopy and small bowel biopsy Celiac, Whipple disease, AIDS ●Breath tests for bacterial overgrowth High false positive, EGD and culture of small intestine aspirate is diagnostic
   • ●Neuroendocrine tumors (Zebras) ●Chronic high volume watery diarrhea with normal osmotic gap that persists during fasting ●Serum VIP (vipoma), calcitonin (medullary thyroid Ca), gastrin (ZES/gastrinoma), glucagon (glucagonoma) Urine for VMA (pheochromocytoma), 5-HIAA (carcinoid tumor), metanephrines (pheo), and histamine

4. Hx&PE

   • HX: ●continuous or intermittent? ●relationship to meals? ●occurs at night or during fasting? ●Medications, diet, and recent psychosocial stressors should be reviewed
   • PE should assess for signs of: ●Malnutrition ●Dehydration ●Inflammatory bowel disease ●Abd. tenderness, distention, bowel sounds, etc

5. SX

   • Stool appearance: ●greasy or malodorous →malabsorption d/o●containing blood or pus→ inflammatory d/o ●Watery→ secretory process
   • Abd. pain: suggests irritable bowel syndrome or inflamm. bowel dz or diverticulitis

6. Summary Approach

   • ●Majority d/t non-infx causes ●Extensive DDX ●Utilize thorough medical hx & stool type (bloody, fatty, watery) to narrow DDX & target work-up ●Non-specific therapy for mild to moderate dz helpful while awaiting dx work-up
   • ●48 to 72 hr stool collection for weight & fecal fat to r/o functional dz if hx & initial screening tests are unrevealing ●If stool collection indicates a true diarrhea, try to focus work-up based on the category of diarrhea ➧Start w/ common, easily treated d/o's before progressing to rare refractory conditions ●When specific dx made, specific therapy often effective

7. Generally > 4 wks, but may vary w/ pt