Diarrhea Comprehensive Notes

Diarrhea Definition

  • Loosely defined as the passage of abnormally liquid or unformed stools at an increased frequency (Harrison's).

  • Increased frequency of bowel movements, increased stool liquidity, a sense of fecal urgency, or fecal incontinence (Doc Pascua- Module).

Stool Consistency

  • Increased fluidity.

  • Difficult to quantitate; most patients will tell you that they have fluid or watery stools.

Stool Frequency

  • ≥3\geq 3 Bowel movements.

Stool Weight

  • 200g/day200g/day – ULN (Upper Limit of Normal) in Western countries. No formal definition based on stool weight in our country.

  • >200g/d stool weight (Harrison's).

  • In infants and children, this would result in stool output >10g/kg/24hr (Doc Pascua’ s Lecture).

  • Diarrhea should not be defined solely in terms of fecal weight.

  • Represents a protective response to different intestinal insults: DEFENSE MECHANISM OF THE BODY TO GET RID OF INTESTINAL PATHOGENS.

Signs and Symptoms

  • Loose, watery stools.

  • Abdominal cramps.

  • Abdominal pain.

  • Fever.

  • Blood in the stool.

  • Mucus in the stool.

  • Bloating.

  • Nausea.

  • Urgent need to have a bowel movement.

History

Duration of Symptoms

  • <2 weeks: acute

  • 2-4 weeks: persistent

  • >4 weeks: chronic

Severity of Diarrhea

  • Acute weight loss (good marker).

Stool Frequency

  • Easiest characteristic for patients to define.

  • Does not necessarily correlate with stool weight.

Stool Volume

  • Large volume - painful stools (may point to a distal colonic site of pathology: LEFT COLON).

  • Small Volume - painless stools (may suggest right colonic or small source: SMALL INTESTINE/ RIGHT COLON).

Stool Characteristics (very important)

  • Presence of blood, mucus, pus, oil droplets, or food particles.

Relationship of Defecation to Meals or Fasting

  • In osmotic diarrhea, it goes away with fasting or stop the offending agents.

Passage of Stools During the Day vs. the Night, and Presence of Fecal Urgency or Incontinence.

  • Important to ask, do they have diarrhea at night, meaning are they awakened by the diarrhea, that suggests an organic problem, maybe a malignancy.

Medical History

  • Medications.

  • Previous Surgery: obstruction from previous surgery can cause diarrhea.

  • Radiation therapy – particularly those with rectal malignancy because it can result to radiation proctitis.

Diet

  • Poorly absorbable carbohydrates (fructose, sugar, alcohols, sorbitol, or mannitol).

  • Those who are fun drinking diet soda as a security blanket for weight loss - coke zero those drinks contain sorbitol, and some people experience diarrhea with those kinds of drinks because they are poorly absorbable.

  • Excessive coffee consumption.

Recent Foreign Travel

  • Think of infectious diarrhea.

Drinking Water Source

Patient’s Occupation

Sexual Orientation

  • Because diarrhea can be a presenting symptom of HIV patient, particularly chronic diarrhea.

Use of Alcohol or Illicit Drug

Physical Examination Findings

  • Patients with acute diarrhea may appear ill, dehydrated, or lethargic depending upon the severity of diarrhea.

  • Hypotension.

  • Fever.

  • Orthostasis.

  • Tachycardia or bradycardia.

  • Tachypnea is caused by metabolic acidosis as a result of severe volume depletion.

  • Skin examination of patients with diarrhea can be done by pinch test. (see Table for Assessment of Dehydration on Additional Information)

    • If the skin on the thigh, calf, or forearm is pinched, it will immediately return to its normal flat state when the pinch is released in normal patients.

      • Mild dehydration (0-5%): Pinch retracts immediately

      • Moderate dehydration (5-10%): Pinch retracts slowly

      • Severe dehydration (>10%): Pinch remains folded

  • Delayed capillary refill.

  • Decreased jugular venous pressure.

  • Abdominal distention.

  • Diffuse abdominal tenderness.

  • Borborygmi.

  • Rigidity and rebound abdominal tenderness.

  • Hepatosplenomegaly is associated with certain infections (Mycobacterium Avium complex, Salmonellosis).

  • In children mostly, the frequent passage of stools causes perineal skin breakdown.

  • Carbohydrate malabsorption secondary to diarrhea may be responsible for more acidic stools, that results in erythema.

  • Bile acid malabsorption leads to diaper dermatitis that is severe and appears as burnt perianal skin.

  • Reductions in muscle and fat mass or peripheral edema may be present in the presence of underlying carbohydrate, fat, and/or protein malabsorption.

  • Giardia can cause intermittent diarrhea and fat malabsorption.

  • Sunken anterior fontanelle.

  • Oral mucosal lesions and angular stomatitis in tropical sprue.

  • Dry mucous membranes and tongue.

  • Muscle weakness and convulsions because of moderate to severe electrolyte imbalance.

Algorithm

  • Figure 1. Algorithm for the Management of Acute (Left) and Chronic Diarrhea (Right) Reference: Harrison’s 20th edition

  • Figure 2. Algorithm for the Management of Diarrhea

Differential Diagnosis

Acute Diarrhea

  1. Infections

    • Bacteria

    • Viruses

    • Parasites

  2. Food Allergies

  3. Food Poisoning

  4. Medications

    • Acid-reducing agents (ex. Histamine H2 receptors)

    • Antacids

    • Antiarrhythmics (ex. Quinidine)

    • Antibiotics (most)

    • Anti-inflammatory agents (Ex. NSAIDS)

    • Antihypertensive (B-adrenergic receptor blocking drugs)

    • Antineoplastic agents (many)

    • Antiretroviral agents

    • Colchicine

    • Heavy metals

    • Herbal products

    • Prostaglandin analogs (ex. Misoprostol)

    • Theophylline

    • Vitamin and mineral supplements

  5. Initial Presentation of Chronic Diarrhea

Chronic Diarrhea

Etiology/Pathophysiology

  • According to Doc Pascua’s Module Lecture Block I- Diarrhea

    • Toxin producers, Enterotoxins, and Enteroadherent pathogens cause NON-INFLAMMATORY DIARRHEA and are mostly characterized by WATERY DIARRHEA.

    • Cytotoxin producers, Invasive organisms, Pathogens under Variable and severe inflammation are pathogens that cause INFLAMMATORY DIARRHEA, and manifestations include FEVER AND MORE OF BLOODY DIARRHEA.

Other Etiologic Consideration: (5 high-risk groups)

  1. Travelers

    • Most commonly due to ETEC/ EAEC

    • Others: Campylobacter, Shigella, Aeromonas, Norovirus, Coronavirus, and Salmonella

  2. Consumer of Certain Foods

    • Chicken - Salmonella, Campylobacter, or shigella

    • Undercooked hamburger - EHEC

    • Fried rice and other heated food - Bacillus cereus

    • Mayonnaise or creams - S. aureus and Salmonella

    • Eggs - Salmonella

    • Soft cheese - Listeria

    • Raw seafood - Vibrio, Salmonella, or acute Hep A

  3. Immunodeficient states

    • Mycobacterium

    • Viruses (CMV, adenovirus, and HSV)

    • Protozoa (Cryptosporidium, Isospora)

    • STD (Neisseria, Treponema, Chlamydia)

  4. Daycare attendees and their family members

    • Shigella, Giardia, Cryprtosporidium, Rotavirus

  5. Institutionalized persons

    • Most commonly C. Difficile

Diagnostics and Expected Results

  1. CBC

    • Anemia

    • Hemoconcentration – indicates hydration status

    • Abnormal WBC

      • Viral: Normal WBC and diff ct or lymphocytosis

      • Bacterial (invasive organisms): Leukocytosis

      • Salmonellosis: Neutropenia

  2. BUN and Crea

    • Fluid and electrolyte depletion and its effect on kidney function

    • You would find prerenal azotemia in these cases.

  3. Stool exam

    • Cornerstone of diagnosis in suspected infectious diarrhea

    • Wright stain and microscopy – detect WBC; accuracy - dependent on the skill and experience of the observer

    • Calprotectin and lactoferrin – sensitive and specific for the detection of neutrophils

    • Stool culture – unlikely to grow pathogenic bacteria in the absence of fecal leukocytes; useful for inpatients

    • C. difficile toxin assay – hospitalized patients in whom acute diarrhea develops while in the hospital; previous treatment with antibiotics in the preceding 3 months

    • Enzyme-linked immunosorbent assay (ELISAs) – giardiasis and cryptosporidiosis

    • Serologic testing for amoebiasis – more accurate than stool microscopy

  4. Abdominal CT scan and other Abdominal imaging – assess colitis, ileus, or megacolon in toxic patients

  5. Proctoscopy or flexible sigmoidoscopy, Colonoscopy

    • Considered in patients who are clearly toxic with infection, (+) blood in the stool, or have persistent acute diarrhea – meaning >7 days

  6. Biopsy - Mucosal biopsy specimens obtained even if the mucosa does not appear to be grossly inflamed or normal because some mucosa appears normal particularly in patients with microscopic colitis.

Management of Acute and Chronic Diarrhea

Acute Diarrhea

Supportive

  • Fluid repletion and Oral Sugar- Electrolyte Solution

  • IV Hydration for profoundly hydrated patients

Antisecretory Agents

  • Loperamide 4mg initially, then 2 mg after each loose stool (not exceed 8 mg day) *avoided on febrile dysentery

  • Bismuth Subsalicylate To reduce vomiting C/I to immunocompromised and those with renal impairment

Antibiotics

*Indicated to ELDERLY, IMMUNOCOMPROMISED PX AND THOSE WITH MECHANICAL HEART VALVES OR RECENT VALVULAR GRAFTS- whether or not a causative organism is discovered.

  • Commonly Used:

    • Ciprofloxacin 500 mg PO q12hr for 5-7 days (empiric tx for febrile dysentery)

    • Metronidazole 500 mg PO q12hr for 5- 7 days (empiric tx for suspected giardiasis)

Chronic Diarrhea

Mild to moderate watery Diarrhea

  • Fluid and electrolyte repletion

  • Mild opiates:

    • Diphenoxylate 5 mg q6hr

    • Loperamide 4mg initially, then 2 mg after each loose stool

More Severe Diarrhea

  • Fluid and electrolyte repletion

  • Codeine and tincture of opium (avoided in severe inflammatory bowel disease because it increases the risk for toxic megacolon)

Etiologic-directed Strategies

  • Lactose intolerance - lactose-restricted diet

  • Chronic pancreatitis - pancreatic enzyme replacement therapy

  • Bile acid-induced Diarrhea - Bile-acid-binding resin

Additional Information

Assessment of Dehydration

  • Source: The CPG on the Management of Acute Infectious Diarrhea in Children and Adults was developed with funding from: Department of Health

Home-Made Oral Rehydration Solution (ORESOL) Doc Pascua’s Lecture

  • 1 LITER OF WATER

  • 6 LEVEL OF TEASPOON OF SUGAR

  • HALF TEASPOON OF SALT

DOH

  • 1 LITER OF WATER

  • 4 TEASPOONS OF SUGAR

  • 1 TEASPOON OF SALT

Bristol Stool Chart

  • Aka Meyer’s Chart

  • Diagnostic medical tool designed to classify the form of human feces into seven categories. It is used in both clinical and experimental fields

References:

  1. Harrison’s IM 20th Ed

  2. IM Plat 3rd ed

  3. CPG on the Management of Acute Infectious Diarrhea in Children and Adults was developed with funding from the Department of Health

  4. Doc Pascua’s Module Lecture on Block 1- Diarrhea