CODES
ICD9
964.0 Poisoning by iron and its compounds
ICD10
- T45.4X1A Poisoning by iron and its compounds, accidental, init
- T45.4X4A Poisoning by iron and its compounds, undetermined, init
IRRITABLE BOWEL SYNDROME
Scott A. Miller
BASICS
DESCRIPTION
- Syndrome of abdominal pain or discomfort associated with altered bowel habits and no other pathology explaining symptoms
- Prevalence estimated to be 10–20%
ETIOLOGY
- Uncertain pathophysiology, but many possibilities
- Altered GI motility:
- Increased gut sensitivity (visceral hyperalgesia):
- Exaggerated response to normal GI physiology
- Mucosal inflammation:
- Postinfectious:
- After bacterial enteritis, 10% have persistent IBS symptoms
- Mucosal lymphocyte infiltration
- Altered microflora in small bowel or feces
- Food sensitivity is a possibility but not proven
- Psychosocial dysfunction:
- More anxiety, somatoform disorders, and history of abuse in patients who seek care
- No evidence of increased psychiatric illness in those who do not seek care
DIAGNOSIS
SIGNS AND SYMPTOMS
- Abdominal pain or discomfort:
- Altered stool frequency
- Altered stool consistency
- Bloating or distention
- Passage of mucus
- Feeling of incomplete emptying
ALERT
- Consider further diagnostic workup if any of the following “alarm” features are present:
- Onset >50
- Nocturnal symptoms
- Unintentional weight loss
- Iron-deficiency anemia
- Hematochezia
- Family history of colorectal cancer, inflammatory bowel disease, or celiac sprue
History
- Rome III diagnostic criteria: Recurrent abdominal pain or discomfort 3 days/mo in the last 3 mo associated with ≥2 of:
- Improvement with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form (appearance) of stool
- Other symptoms consistent with IBS:
- Abdominal distention or bloating
- Passage of mucus in stools
- Altered stool passage (straining, urgency, or feeling of incomplete evacuation)
- Postprandial upper abdominal discomfort
- Symptoms of gastroesophageal reflux
- Flatulence
- Female < male, 1.5–2:1 overall, higher in those who seek care
Physical-Exam
- Usually well appearing with normal physical
- May have tender sigmoid or palpable sigmoid cord
ESSENTIAL WORKUP
Clinical diagnosis: Careful history crucial
DIAGNOSIS TESTS & NTERPRETATION
Lab
- Typically no abnormalities found
- Labs to be considered (to exclude other pathology), but not required:
- CBC:
- Should not have leukocytosis or anemia
- Normal ESR and CRP useful in excluding inflammatory conditions
- Serum chemistry, thyroid studies unlikely to be useful
- Stool for ova and parasites:
- Most useful for diarrhea workup
- Consider outpatient serum test for celiac
Imaging
Only necessary if excluding emergent pathology
Diagnostic Procedures/Surgery
Colonoscopy/flexible sigmoidoscopy for select patients (outpatient)
DIFFERENTIAL DIAGNOSIS
- Celiac disease
- Inflammatory bowel disease:
- Ulcerative colitis/proctitis
- Crohn's disease
- Infectious enteritis
- Small-intestinal bacterial overgrowth
- Lactose intolerance
- Colorectal cancer
- Diverticular disease
- Biliary disease
- Diabetic gastroparesis
- Pancreatitis
- Thyroid malfunction
- Obstruction
- Peptic ulcer disease
- Acute intermittent porphyria
TREATMENT
PRE HOSPITAL
No specific treatment required
INITIAL STABILIZATION/THERAPY
- Symptomatic treatment
- Pain control
- Administer fluids if dehydrated
ED TREATMENT/PROCEDURES
- Empathetic approach and therapeutic physician–patient relationship is most important.
- Exercise:
- Improves gastric emptying and constipation
- Diet:
- Many believe symptoms have a food trigger, but not yet proven.
- Exclusion diets starting with gluten or lactose can be empirically considered.
- Avoid beans, cabbage, uncooked broccoli, other flatulent foods if symptomatic.
- Constipation symptoms:
- High-fiber diet, fiber supplements
- Abdominal pain:
- Antispasmodics like hyoscyamine and dicyclomine may be helpful short-term
- Probiotics:
- Bifidobacteria appear more effective than lactobacilli
- Antidepressants:
- TCAs and possibly SSRIs appear to be effective at relieving global IBS symptoms and reducing abdominal pain.
- Psychological therapies appear effective.
MEDICATION
First Line
- Dicyclomine: 10–20 mg PO q6h
- Hyoscyamine: 0.125–0.25 mg PO or sublingual not to exceed 12 tab/day
Second Line
- Amitriptyline: 25 mg PO at bedtime (or another TCA)
- Fluoxetine: 20 mg PO daily (or another SSRI)
- Bifidobacteria probiotic
FOLLOW-UP
DISPOSITION
Admission Criteria
Uncertain diagnosis with suspicion of an emergent abdominal condition
Discharge Criteria
Almost all patients can be managed as outpatients.
Issues for Referral
Some may benefit from GI or psychiatric referral.
FOLLOW-UP RECOMMENDATIONS
Most important is follow-up with primary care physician to foster a therapeutic physician–patient relationship.
PEARLS AND PITFALLS
- Beware of other emergent pathology.
- IBS is common, so it is likely the underlying cause of many abdominal workups done in the ED.
ADDITIONAL READING
- American College of Gastroenterology Task Force on Irritable Bowel Syndrome, Brandt LJ, Chey WD, et al. An evidence-based position statement on the management of irritable bowel syndrome.
Am J Gastroenterol
. 2009;104 (Suppl 1):S1–S35.
- Whelan K, Quigley EM. Probiotics in the management of irritable bowel syndrome and inflammatory bowel disease.
Curr Opin Gastroenterol
. 2013;29(2):184–189.
- Videlock EJ, Chang, L. Irritable bowel syndrome: Current approach to symptoms, evaluation, and treatment.
Gastroenterol Clin North Am
. 2007;36(3):665–685, x.
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