Chronic Diarrhea

From Anvita Health Wiki

Contents 1 Introduction 2 Etiology 3 Laboratory 4 Diagnostic-procedures 5 Radiology 6 Management 7 More General Terms 8 Additional Terms 9 References

Introduction

• Diarrhea persisting longer than 3-4 weeks, continuous or episodic in nature. AIDS has contributed significantly to the incidence of chronic diarrhea.

Etiology

• irritable bowel syndrome (most common cause)

• frequent incomplete evacuations
• daytime diarrhea
• often alternating with constipation
• aggravated by stress
• generally begins in adolescence

• pharmacologic agents (see pharmaceutical agents associated with diarrhea)
• diet (see acute diarrhea)
• infection (see infectious diarrhea)

• Giardia lamblia
• Entamoeba histolytica
• Campylobacter
• Cryptosporidium
• Mycobacterium avium-intracellulare
• Mycobacterium tuberculosis
• Isospora
• Cytomegalovirus
• Microsporidia

• osmotic/malabsorption

• lactose intolerance
• pancreatic insufficiency
• bile acid malabsorption
• bacterial overgrowth
• celiac disease
• Whipple's disease
• abetalipoproteinemia
• short bowel syndrome

• tumor

• colorectal carcinoma
• pancreatic carcinoma
• villous adenoma

• inflammatory bowel disease

• ulcerative proctitis
• ulcerative colitis
• Crohn's disease

• consider in elderly with non-specific symptoms & indolent course

• ischemic colitis
• radiation colitis
• eosinophilic gastroenteritis

• endocrine ( secretory)

• hyperthyroidism
• diabetes mellitus
• hypoadrenalism
• multiple endocrine neoplasias

• gastrinoma ( Zollinger-Ellison syndrome)
• vasoactive intestinal polypeptide ( VIP)-producing tumor
• carcinoid
• medullary carcinoma of the thyroid
• villous adenoma of the rectum

• laxative abuse
• fecal impactation

• especially nursing home patients on tricyclic antidepressants ( TCA) & anticholinergic agents

• microscopic or collagenous colitis (secretory)
• fecal incontinence
• common variable immunodeficiency
• chronic idiopathic secretory diarrhea

Laboratory

• also see acute diarrhea
• exclude infectious etiology (see acute diarrhea)
• exclude lactose intolerance

• lactose-restriction
• lactose tolerance test

• serum chemistries

• K+, Ca+2, cholesterol, albumin, total protein, glucose, thyroxine ( T4), cortisol (8 AM), amylase, serum iron, vitamin B12

• HIV testing
• complete blood count ( CBC) with differential including eosinophil count
• stool volume
• fecal electrolytes (Na+, K+, Cl-)
• fecal osmolality

• 400 mOsm in osmotic diarrhea,
• 290 in secretory diarrhea

• fecal pH < 6.0 suggests carbohydrate malabsorption
• fecal osmolal gap

• osmolality - (Na+ + K+) x 2
• > 100 in osmotic diarrhea
• < 50 in secretory diarrhea

• stool alkalinization for phenolphthalein use/abuse
• stool Mg+ for Mg+ abuse
• evidence of multiple endocrine neoplasia

• urinary 5HIAA, serum gastrin, calcitonin, VIP, glucagon, somatostatin

• heavy metal analysis (as indicated)

• arsenic, mercury, lead, cadmium

• tests which may be useful

• glucose tolerance test
• prothrombin time
• erythrocyte sedimentation rate (ESR)
• tests for celiac sprue
• secretin-stimulation test for pancreatic insufficiency
• neuropeptide assays for neuroendocrine neoplasms

Diagnostic-procedures

• (as indicated)
• flexible sigmoidoscopy

• without enema prep
• biopsy
• culture

• colonoscopy
• malabsorption work-up

• 72 hour fecal fat (> 6 g/day on a diet containing 80-100 g/day fat is abnormal)
• D-Xylose absorbtion

• 25 g of D-xylose is given orally
• < 4.5 g of xylose in 5 hour urine collection is abnormal

• Schilling or hydrogen breath test for bacterial overgrowth
• small bowel biopsy, aspirate, culture
• bentiromide test for pancreatic function
• gluten sensitivity screen - gliadin antibody

• therapeutic trials

• restricted diets (i.e. gluten)
• antibiotics - tetracycline, metronidazole

Radiology

• plain abdominal radiograph

• obstruction
• pancreatic calcifications

• air-contrast barium enema

• avoid in patients with ulcerative colitis & Crohn's disease for risk of toxic megacolon

• upper GI series with small bowel follow-through

• Crohn's disease
• Whipple's disease
• celiac sprue

Management

• general

• rehydrate
• eliminate causative foods & pharmacologic agents

• management of specific etiologies

• irritable bowel syndrome

• psyllium
• dicyclomine ( Bentyl) 10 mg PO TID

• lactose intolerance

• discontinue lactose from diet or Lactaid-containing products
• calcium supplementation ( calcium carbonate)

• 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

• 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

• diabetes mellitus - clonidine, octreotide ( Sandostatin)
• chronic secretory diarrhea - octreotide ( Sandostatin)
• intractable diarrhea - cholestyramine
• Most AIDS patients have at least 1 episode of diarrhea

• symptomatic treatment of stool culture negative diarrhea

More General Terms

• diarrhea
• chronic gastrointestinal disease

Additional Terms

• Campylobacter
• cholestyramine (Questran)
• clonidine (Catapres)
• Cryptosporidium
• cytomegalovirus (CMV, human herpesvirus 5)
• diabetes mellitus
• Entamoeba histolytica
• fecal impactation
• Giardia lamblia; includes giardiasis (beaver fever)
• hyperthyroidism
• inflammatory bowel disease
• irritable bowel syndrome (IBS)
• Isospora
• malabsorption
• microscopic (collagenous or lymphocytic) colitis
• microsporidia
• multiple endocrine neoplasia (MEN)
• Mycobacterium avium-complex (MAC, Mycobacterium avium intracellulare, MAI)
• Mycobacterium tuberculosis (MTB)
• octreotide (Sandostatin)
• pharmaceutical agents associated with diarrhea

References

1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 305-306
2. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
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

chronic diarrhea