Diarrhea and Constipation

Question 0

Causes of Acute, Persistent, Chronic Diarrhea

Answer 0

Acute

• Infection - most
• medications, toxic ingestions, ischemia, and other conditions

Persistent

• Giarda - common
• C. difficile, E. hystolitica, Cryptosporidium, Campylobacter

Chronic
Secretory: Medications, Bowel resection, mucosal disease, or enterocolic fistula, hormones, Congenital defects in ion absorption
Osmotic: Osmotic laxatives, Carbohydrate malabsorption
Steatorrheal : Fat malabsorption, Intraluminal maldigestion, Mucosal malabsorption, Postmucosal lymphatic obstruction
Inflammatory: Primary or secondary forms of immunodeficiency, Eosinophilic gastroenteritis
Dysmotility: Hyperthyroidism, carcinoid syndrome, and certain drugs
Factitial : Munchausen syndrome (deception or self-injury for secondary gain) or eating disorders, some patients covertly self-administer laxatives alone or in combination with other medications (e.g., diuretics)

Steatorrhea is defined as stool fat exceeding the normal 7 g/d;
rapid-transit diarrhea may result in fecal fat up to 14 g/d;
daily fecal fat averages 15–25 g with small intestinal diseases and is often >32 g with pancreatic exocrine insufficiency.
Intraluminal maldigestion, mucosal malabsorption, or lymphatic obstruction may produce steatorrhea.

Question 1

Diarrhea vs Pseudodiarrhea vs Fecal Incontinence

Acute, Persistent, Chronic Diarrhea?

Answer 1

Diarrhea-passage of abnormally liquid or unformed stools at an increased frequency

Pseudodiarrhea, or the frequent passage of small volumes of stool, is often associated with rectal urgency and accompanies IBS or proctitis.

Fecal incontinence is the involuntary discharge of rectal contents and ; caused by neuromuscular disorders or structural anorectal problems.

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Question 2

Indication for stool evaluation

Answer 2

profuse diarrhea with dehydration
grossly bloody stools
fever ≥38.5°C (≥101°F)
duration >48 h without improvement
recent antibiotic use
new community outbreaks
associated severe abdominal pain in patients >50 years
elderly (≥70 years)
 immunocompromised patients

Question 3

Physical Examination in Patients With Chronic Diarrhea

Answer 3

1. Are there general features to suggest malabsorption or inflamma- tory bowel disease (IBD) such as anemia, dermatitis herpetiformis, edema, or clubbing?
2. Are there features to suggest underlying autonomic neuropathy or collagen-vascular disease in the pupils, orthostasis, skin, hands, or joints?
3. Is there an abdominal mass or tenderness?
4. Are there any abnormalities of rectal mucosa, rectal defects, or altered anal sphincter functions?
5. Are there any mucocutaneous manifestations of systemic disease such as dermatitis herpetiformis (celiac disease), erythema nodo- sum (ulcerative colitis), flushing (carcinoid), or oral ulcers for IBD or celiac disease?

Question 4

What is constipation? Causes?

Answer 4

Constipation refers to persistent, difficult, infrequent, or seemingly incomplete defecation

Causes in adults
A. Recent onset
Colonic obstruction
Anal sphincter spasm
Medications

B. Chronic
Irritable bowel syndrome
Medications
Colonic pseudoobstruction
Disorders of rectal evacuation
Endocrinopathies
Psychiatric disorders
Neurologic disease
Generalized muscle disease

Question 5

History-taking for constipation

Answer 5

frequency (e.g., fewer than three bowel movements per week),
consistency (lumpy/hard),
excessive straining,
prolonged defecation time,
need to support the perineum or digitate the anorectum