IBS

Diagnostic Criteria for IBS

Abdominal discomfort or pain, for at least 12 weeks (which need not be consecutive) in the preceding 12 months, with two of the following features:
	Relief with defecation
	Onset associated with a change in stool frequency
	Onset associated with a change in form or appearance of stool
These additional symptoms cumulatively support the diagnosis of IBS:
	Abnormal stool frequency (more than three times per day or less than three times per week)
	Abnormal stool form (loose and watery or lumpy and hard)
	Abnormal stool passage (urgency, frequency, feeling of incomplete evacuation)
Passage of mucus (white material)
Bloating or sensation of abdominal distention

Signs and Symptoms Suggesting Alternative Diagnosis to Irritable Bowel Syndrome

Sign or symptoms	Suggested diagnosis
Alarm factors
Anemia	Cancer, IBD
Chronic severe diarrhea	Cancer, infection, IBD
Family history of colon cancer	Cancer
Hematochezia, melena, or other signs of intestinal bleeding	Cancer, arteriovenous malformation, colonic polyps, IBD
Recurrent fever	Infection, IBD
Weight loss	Cancer, IBD
Other signs and symptoms
Travel to areas with parasitic diseases	Infection
Family history of colon cancer, irritable bowel syndrome, celiac disease	Cancer, celiac disease
Signs or symptoms of malabsorption	Celiac disease
Nighttime symptoms (e.g., encopresis)	Infection, trauma
Onset after 50 years of age	Cancer
Arthritis	Arthritis
Thyroid dysfunction

Medications for Treatment of Irritable Bowel Syndrome

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Treatment	Initial dosage	Maintenance dosage	Cost (generic)*	Comments
Dicyclomine (Bentyl)	20 mg fourtimes per day	20 to 40 mg four times per day	$63 (22 to 82)	If not effective in two weeks, discontinue.
Hyoscyamine (Levsin)	0.125 to 0.250 mg every four hours	Same	145 (52 to 61)	Anticholinergic effects; maximum 1.5 gm per day
Loperamide (Imodium)	4 mg	4 to 8 mg per day	49 (15 to 42)	—
Amitriptyline	10 to 25 mg every night at bedtime	10 to 100 mg every night at bedtime	8 (2 to 10)	Large dosing range; start low, and titrate as needed.
Desipramine (Norpramin)	10 to 50 mg every night at bedtime	10 to 150 mg every night at bedtime	21 (12 to 21)	Large dosing range; start low, and titrate as needed.
Alosetron (Lotronex)	1 mg per day for four weeks	1 mg once or twice per day	216	Use in women with diarrheapredominant irritable bowel syndrome; use with caution; available only through prescribing program; associated with ischemic colitis.
Tegaserod (Zelnorm)	6 mg twice per day for four to 12 weeks	Same	169	Use in constipation with same caveats as alosetron; only indicated for 12 weeks of therapy.