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chronic diarrhea

Diarrhea persisting > 4 weeks, continuous or episodic in nature. [2,8] AIDS has contributed significantly to the incidence of chronic diarrhea. Etiology: 1) irritable bowel syndrome (most common cause) a) frequent incomplete evacuations b) daytime diarrhea c) often alternating with constipation d) aggravated by stress e) generally begins in adolescence 2) pharmacologic agents (see pharmaceutical agents associated with diarrhea) 3) diet (see acute diarrhea) 4) infection (see infectious diarrhea) a) Giardia lamblia b) Entamoeba histolytica c) Campylobacter d) Cryptosporidium e) Mycobacterium avium-intracellulare f) Mycobacterium tuberculosis g) Isospora h) Cytomegalovirus i) Microsporidia j) C difficile colitis 5) osmotic/malabsorption a) carbohydrate malabsorption - lactose intolerance due to lactase deficiency - fructose intolerance, sorbitol, mannitol b) pancreatic insufficiency c) bile acid malabsorption (ileal resection) [10] d) bile acid deficiency e) bacterial overgrowth in small intestine f) celiac disease g) Whipple's disease h) abetalipoproteinemia i) short bowel syndrome 6) tumor a) colorectal carcinoma b) pancreatic carcinoma c) villous adenoma 7) inflammatory bowel disease a) ulcerative proctitis b) ulcerative colitis c) Crohn's disease - consider in elderly with non-specific symptoms & indolent course d) microscopic colitis (secretory) - collagenous colitis, lymphocytic colitis e) ischemic colitis f) radiation colitis g) eosinophilic gastroenteritis 8) endocrine (secretory) a) hyperthyroidism b) diabetes mellitus c) hypoadrenalism d) multiple endocrine neoplasias 1] gastrinoma (Zollinger-Ellison syndrome) 2] vasoactive intestinal polypeptide (VIP)-producing tumor 3] carcinoid 4] medullary carcinoma of the thyroid 5] villous adenoma of the rectum 9) motility disorders - postoperative (vagotomy, dumping syndrome - scleroderma - laxative abuse 10) fecal impactation - especially nursing home patients on tricyclic antidepressants (TCA) & anticholinergic agents 11) fecal incontinence 12) common variable immunodeficiency 13) factitious diarrhea 13) chronic idiopathic secretory diarrhea History: - diarrhea pattern & duration - Rome criteria for irritable bowel syndrome - extraintestinal manifestations* - diet - lactose, fructose, artificial sweeteners - recent travel - sick contacts - medications * history or evidence of inflammatory bowel disease Clinical manifestations: - lack of nocturnal symptoms & improvement of symptoms with fasting suggests osmotic diarrhea - nocturnal symptoms suggests secretory diarrhea Laboratory: 1) also see acute diarrhea 2) exclude infectious etiology - ova & parasites for giardiasis [2] - infectious causes of chronic diarrhea uncommon in immunocompetent adults in developed countries, except for giardiasis - also see acute diarrhea for other infectious causes of diarrhea 3) exclude lactose intolerance a) lactose-restriction b) lactose tolerance test 4) serum chemistries - serum K+, serum Ca+2, serum cholesterol, serum albumin, serum total protein, serum glucose, serum thyroxine (serum T4), cortisol (8 AM), amylase, serum iron, vitamin B12 5) HIV testing 6) complete blood count (CBC) with differential including eosinophil count 7) 72 hour stool collection a) stool volume b) fecal fat to confirm steatorrhea 8) fecal electrolytes (Na+, K+, Cl-) 9) fecal osmolality a) 400 mOsm in osmotic diarrhea, b) 290 in secretory diarrhea 10) fecal pH < 6.0 suggests carbohydrate malabsorption 11) fecal osmolal gap a) osmolality (290) - (Na+ + K+) x 2 b) > 100 in osmotic diarrhea c) < 50 in secretory diarrhea 12) stool alkalinization for phenolphthalein use/abuse - stool or urine laxative screen for laxative abuse 13) stool Mg+ for Mg+ abuse 14) calprotection in stool for inflammatory bowel disease [8] 15) bile acids in stool [8] (rather than empiric treatment) 16) fecal elastase for fat malabsorption [8] - reduced fecal elastase suggests chronic pancreatitis 17) tissue transglutaminase Ab for celiac sprue 18) evidence of multiple endocrine neoplasia - urinary 5HIAA, serum gastrin, calcitonin, VIP, glucagon, somatostatin 19) heavy metal analysis (as indicated) - arsenic, mercury, lead, cadmium 20) tests which may be useful a) glucose tolerance test b) prothrombin time c) erythrocyte sedimentation rate (ESR) d) secretin-stimulation test for pancreatic insufficiency e) neuropeptide assays for neuroendocrine neoplasms - only after other causes have been excluded [8] Special laboratory: 1) reserve testing for patients whose symptoms do not suggest irritable bowel syndrome [2] 2) colonoscopy - rule out colon cancer in patients > 50 years [1] - rule out microscopic colitis with biopsy of right & left colon [2,8] 3) malabsorption work-up a) 72 hour fecal fat (> 6 g/day on a diet containing 80-100 g/day fat is abnormal) b) D-Xylose absorption 1] 25 g of D-xylose is given orally 2] < 4.5 g of xylose in 5 hour urine collection is abnormal c) Schilling or hydrogen breath test for bacterial overgrowth - empiric trial of antibiotics rather than breath testing for diagnosis of small intestinal bacterial overgrowth [8] d) small bowel biopsy, aspirate, culture e) bentiromide test for pancreatic function f) gluten sensitivity screen - gliadin antibody 4) video capsule endoscopy for small bowel pathology Radiology: 1) reserve imaging for patients whose symptoms do not suggest irritable bowel syndrome [2] 2) plain abdominal radiograph a) obstruction b) pancreatic calcifications 3) air-contrast barium enema - avoid in patients with ulcerative colitis & Crohn's disease for risk of toxic megacolon - avoid 4) upper GI series with small bowel follow-through a) Crohn's disease b) Whipple's disease c) celiac sprue d) barium may be best avoided [8] 5) use MRI rather than CT for evaluation of chronic pancreatitis or structural abnormalities of small bowel Differential diagnosis: - irritable bowel syndrome - bloating, abdominal discomfort relieved by bowel movement - no weight loss, no alarm features - rule out celiac disease - microscopic colitis - nocturnal diarrhea mainly in women 45-60 years - colonoscopy normal; biopsy needed to confirm diagnosis - stop NSAIDs, proton pump inhibitors - carbohydrate intolerance - lactose intolerance - diarrhea with dairy products - hydrogen breath test or empiric exclusion of lactose from diet - fructose intolerance - hydrogen breath test or empiric exclusion of fructose from diet - sorbitol - small intestinal bacterial overgrowth - nocturnal diarrhea & diabetes mellitus or systemic sclerosis - hydrogen breath test or empiric antibiotics - common variable immunodeficiency or selective IgA deficiency - pulmonary disease &/or recurrent giardiasis - immunoglobulin in serum - sweat test for cystic fibrosis - serrupticious diarrhea (laxative abuse) - fecal osmolality, fecal electrolytes, fecal magnesium, laxative screen - carcinoid syndrome - secretory diarrhea, flushing - 5-HIAA in 24 hour urine - inflammatory bowel disease - diarrhea, abdominal pain, fecal calprotectin positive - medications - proton pump inhibitors, magnesium, metformin, colchicine, antibiotics [2] Management: 1) general a) rehydrate b) eliminate causative foods & pharmacologic agents (see pharmaceutical agents associated with diarrhea) 2) therapeutic trials a) restricted diets (i.e. gluten) b) antibiotics - tetracycline, metronidazole - empiric trial of antibiotics rather than breath testing for diagnosis of small intestinal bacterial overgrowth [8] 3) management of specific etiologies a) irritable bowel syndrome - psyllium - dicyclomine (Bentyl) 10 mg PO TID b) lactose intolerance - discontinue lactose from diet or Lactaid-containing products - calcium supplementation (calcium carbonate) c) malabsorption - pancreatic insufficiency - pancrelipase (Viokase, Pancrease, Cotazym, Ku-Zyme) 1-3 tabs PO with meals - bacterial overgrowth - Bactrim DS PO BID - celiac disease - avoid wheat, barley, rye flour - cholestryamine for chronic watery diarrhea after ileal resection - disruption of enterohepatic circulation by inadequate bile acid resorption d) inflammatory bowel disease - ulcerative proctitis - hydrocortisone 100 mg retention enema (Cortenema) QHS for 21 days, - 100 mg hydrocortisone hemisuccinate blended with 60 mL of canola oil - mesalamine (Rowasa) 4 gm enema - ulcerative colitis - prednisone 60 mg PO QD until remission - maintenance - prednisone 15-30 mg QD - sulfasalazine or mesalamine (Asacol, Pentasa) PO 2-4 g QD - steroid enema - Crohn's disease: as for ulcerative colitis, plus: - antibiotic, folic acid, antimotility agent - cholestryamine for chronic watery diarrhea after ileal resection - disruption of enterohepatic circulation by inadequate bile acid resorption e) diabetes mellitus - clonidine, octreotide (Sandostatin) f) chronic secretory diarrhea - octreotide (Sandostatin) g) intractable diarrhea - cholestyramine h) most AIDS patients have at least 1 episode of diarrhea - symptomatic treatment of stool culture negative diarrhea

Related

acute diarrhea infectious diarrhea; infectious colitis pharmaceutical agents associated with diarrhea

General

diarrhea chronic gastrointestinal disease

References

  1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 305-306
  2. Medical Knowledge Self Assessment Program (MKSAP) 11, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2012, 2015, 2018, 2021. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  3. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 216-218
  4. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 239
  5. Schiller LR Definitions, pathophysiology, and evaluation of chronic diarrhoea. Best Pract Res Clin Gastroenterol. 2012 Oct;26(5):551-62 PMID: 23384801
  6. Murray JA, Rubio-Tapia A. Diarrhoea due to small bowel diseases. Best Pract Res Clin Gastroenterol. 2012 Oct;26(5):581-600 PMID: 23384804
  7. Schiller LR, Pardi DS, Spiller R et al Gastro 2013 APDW/WCOG Shanghai working party report: chronic diarrhea: definition, classification, diagnosis. J Gastroenterol Hepatol. 2014 Jan;29(1):6-25 PMID: 24117999
  8. Arasaradnam RP, Brown S, Forbes A et al. Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition. Gut 2018 Apr 13 PMID: 29653941 Free Article http://gut.bmj.com/content/early/2018/04/13/gutjnl-2017-315909
  9. DuPont HL. Persistent Diarrhea: A Clinical Review. JAMA. 2016 Jun 28;315(24):2712-23. Review. PMID: 27357241
  10. Sadowski DC, Camilleri M, Chey WD et al Canadian Association of Gastroenterology Clinical Practice Guideline on the Management of Bile Acid Diarrhea. J Can Assoc Gastroenterol. 2020 Feb;3(1):e10-e27. PMID: 32010878 PMCID: PMC6985689 Free PMC article.