Approach To Chronic Diarrhea

Outline:

Definition

Classification

EPIDEMIOLOGY ETIOLOGY

EVALUATION

HISTORY P/E

Lab Investigations

Mangment

Definition:

•Traditionally, diarrhea has been defined as an increase in daily stool weight (> 200 g/day). --- impractical

•Diarrhea can be considered an increase in stool frequency (3 or more stools/day) and/or the presence of loose or liquid stools.

Classification:

Diarrhe

a

Acute Chronic

Classification:•By volume (large vs. small),

•By pathophysiology (secretory vs. osmotic),

•By stool characteristics watery vs. fatty vs. inflammatory.

Chronic Diarrhea:

•The American Gastroenterological Association suggests that chronic diarrhea should be defined as a decrease in fecal consistency lasting for four or more weeks.

EPIDEMIOLOGY:

•  The prevalence of chronic diarrhea in the general population in developed nations has not been well established, due to differences in study design, definitions, and characteristics of populations that have been sampled.

•Based upon a commonly used definition (ie, the presence of excessive stool frequency) a reasonable approximation is that chronic diarrhea affects approximately 5 percent of the population.

CHRONIC DIARRHEA

• Etiology

The causes of chronic diarrhea may be grouped into six major pathophysiologic categories

Malabsorptive

Secretory

Inflammatory

Motility

Infections

Factitial

1-Malabsorptive Conditions• The major causes of malabsorption are

small mucosal intestinal diseases, intestinal resections,lymphatic obstruction, small intestinal bacterial overgrowth, and pancreatic insufficiency

• In patients with suspected malabsorption, quantification of fecal fat should be performed

2-Secretory Conditions

• Increased intestinal secretion results in a watery diarrhea that may be large in volume (1–10 L/d).

• Here is little change in stool output during the fasting state.

• Major causes include endocrine tumors (stimulating intestinal or pancreatic secretion), bile salt malabsorption (stimulating colonic secretion), and laxative abuse

3-Inflammatory Conditions

• Diarrhea is present in most patients with inflammatory bowel disease (ulcerative colitis, Crohn's disease, microscopic colitis).

• A variety of other symptoms may be present, including abdominal pain, fever and weight loss.

4-Motility Disorders

•Abnormal intestinal motility secondary to systemic disorders or surgery may result in diarrhea due to rapid transit or to stasis of intestinal contents with bacterial overgrowth.

5-Chronic Infections• Chronic parasitic infections may cause diarrhea.

agents most commonly associated with diarrhea include the protozoans Giardia, E histolytica and Cyclospora.

• Immunocompromised patients, especially those with AIDS, are susceptible to a number of infectious agents that can cause acute or chronic diarrhea.

• Chronic diarrhea in AIDS is commonly caused by Cryptosporidium, cytomegalovirus, Isospora belli and Cyclospora.

6-Factitial Diarrhea

• Approximately 15% of patients with chronic diarrhea have factitial diarrhea caused by laxative abuse.

Approach to chronic diarrhea:

AGE

• Young patients ▫ Inflammatory Bowel Disease ▫ Functional bowel disorder (Irritable bowel)

• Older patients ▫ Colon Cancer ▫ Diverticulitis

DIARRHEA PATTERN

• Diarrhea alternates with Constipation

▫ Colon Cancer

▫ Laxative abuse

▫ Diverticulitis

▫ Irritable bowel syndrome.

•Intermittent Diarrhea

▫Diverticulitis

▫ Irritable bowel syndrome.

▫Malabsorption

•Persistent Diarrhea

▫Inflammatory Bowel Disease

▫Laxative abuse

SMALL BOWEL/LARGE BOWEL

•Small intestine or proximal colon involved ▫Large stool Diarrhea ▫Abdominal cramping persists after

Defecation

•Distal colon involved ▫Small stool Diarrhea ▫Abdominal cramping relieved by Defecation

DIURNAL VARIATION• No relationship to time of day:

Infectious Diarrhea

• Morning Diarrhea and after meals ▫ Gastric cause ▫ Irritable bowel syndrome. ▫ Inflammatory Bowel Disease

• Nocturnal Diarrhea (always organic) ▫ Diabetic Neuropathy ▫ Inflammatory Bowel Disease

WEIGHT LOSS•Despite normal appetite

▫Hyperthyroidism ▫Malabsorption

•Associated with fever ▫Inflammatory Bowel Disease

•Weight loss prior to Diarrhea onset ▫Pancreatic Cancer ▫Tuberculosis ▫Diabetes Mellitus ▫Hyperthyroidism ▫Malabsorption

STOOL CHARACTERISTICS

•Blood, pus or mucus:

Chronic Inflammatory Diarrhea

•Foul, bulky, greasy stools: Chronic Fatty Diarrhea

MEDICATION AND DIETARY INTAKE•Drug induced diarrhea.•Food borne illness. •Waterborne illness. •Excessive sorbitol or mannitol. •Excessive coffee or other caffeine.

TRAVEL History:

•Traveler’s diarrhea.

•The most common cause for traveler's diarrhea??

•Infectious diarrhea.

ASSOCIATED SYMPTOMS

•Abdominal pain

•Alternating constipation

•Unintentional wt. loss

•Fever

PAST MEDICAL HISTORY

•Childhood diarrhea-resolves-re-emergence in adulthood– celiac disease

•Uncontrolled diabetes

•Pelvic radiotherapy

PAST SURGICAL HISTORY:

•Bowel resection

•Cholecystectomy

•Jejunoileal bypass

RED FLAGS-suggestive of organic causes• Painless diarrhea• Recent onset in an older patient • Nocturnal diarrhea (especially if wakes patient) • Weight loss • Blood in stool • Large stool volumes: >400 grams stool per day • Anemia • Hypoalbuminemia • increased ESR

PHYSICAL EXAMINATION

GPE

•General appearance and mental status

•Vital signs

•Body weight

•Orthostasis- volume depletion,autonomic dysfunction

•exophthalmos (hyperthyroidism)

• aphthous ulcers (IBD and celiac disease)

• lymphadenopathy (malignancy, infection or Whipple's disease)

•enlarged or tender thyroid (thyroiditis, medullary carcinoma of the thyroid)

•clubbing (liver disease, IBD, laxative abuse, malignancy)

SKIN LESIONS

•dermatitis herpetiformis (celiac disease)

• erythema nodosum (IBD)

•hyperpigmentation (Addison's disease)

ABDOMINAL EXAMINATION• Surgical scars

• abdominal tenderness

• Masses

• Hepatosplenomegaly

PERINEAL AND RECTAL EXAMINATION

•Signs of incontinence –▫skin changes from chronic irritation, ▫gaping anus,▫weak sphincter tone.

•Crohn's disease ▫perianal skin tags▫Ulcers▫ fissures▫ abscesses▫Fistulas▫stenoses.

•Fecal impaction or masses might be noted.

SYSTEMIC EXAMINATION

•wheezing and right-sided heart murmurs (carcinoid syndrome)

•arthritis (IBD, Whipple's disease)

INVESTIGATIONS

BLOOD TESTS

• CBC • TSH • Serum electrolytes • Serum albumin

STOOL EVALUATION• Stool pH (<6 in carbohydrate malabsorption )

• Fecal electrolytes (Fecal sodium and osmolar gap)

▫ Differentiates chronic watery diarrhea category

• Fecal occult blood test

• Fecal leukocytes

•Fecal fat (abnormal if >14 grams/24 hours)

•Stool ova and parasites (2-3 samples)

•Giardia lamblia antigen ▫Indicated for diarrhea >7 days and >10

stools/day

•Clostridium difficle toxin ▫Indicated if recent antibiotics or hospitalization

•Consider testing stools for laxative abuse

ENDOSCOPY•PROCTOSIGMOIDOSCOPY

•An endoscopic evaluation should be considered if there are:

• persistent symptoms, • inconclusive diagnosis, • failure to respond to therapy.

• In patients less than 45 years with typical symptoms of functional bowel disease, normal examination, and normal screening blood tests, a positive diagnosis can be made and no further investigation is necessary

• Patients less than 45 years with chronic diarrhoea and/or atypical symptoms should undergo flexible sigmoidoscopy in the first instance as the diagnostic yield differs little from the use of colonoscopy in this age group

• In patients over 45 years with chronic diarrhoea, colonoscopy (with ileoscopy) is the preferred investigation. This may yield abnormalities in up to 30% of cases, has a better sensitivity than barium enema, and allows sampling of the colonic mucosa for histological examination

Irritable bowel syndrome:“Rome criteria”

• 3 months of continuous or recurring symptoms of abdominal pain or irritation that:▫ May be relieved with a bowel movement,▫ May be coupled with a change in frequency, or▫ May be related to a change in the consistency of stools.

• Two or more of the following are present at least 25 percent (one quarter) of the time:▫ A change in stool frequency (more than 3 bowel movement per

day or fewer than 3 bowel movements per week) ▫ Noticeable difference in stool form (hard, loose and watery stools

or poorly formed stools) ▫ Passage of mucous in stools▫ Bloating or feeling of abdominal distention▫ Altered stool passage (e.g. sensations of incomplete evacuation,

straining, or urgency)

TREATMENT

NON-SPECIFIC THERAPIES•Dietary modifications

▫Smaller, more frequent meals

▫Dec. carbohydrates

▫Dec. fat intake

▫Avoidance of milk

▫Avoid sorbitol and mannitol

•No good evidence to support use of bulking agents

•opioids and opioid agonists ▫Loperamide- first line therapy▫diphenoxylate-atropine (Lomotil )▫Codeine and other narcotics – for

refractory cases

SPECIFIC THERAPIES•Clonidine-

▫Diabetic diarrhea▫moderate and severe diarrhea-predominant

IBS

•Somatostatin ▫refractory diarrhea

AIDS, post chemotherapy.

•bile acid binders (ie, cholestyramine) •pancreatic enzyme supplementation

•antimicrobials –empiric fluoroquinolones therapy

References:

•UP To Date.

•Davidson's Principles and Practice of Medicine.

•The American Gastroenterological Association (AGA) technical review website.

Thank You!