CategoryExamplesType of IBS*Comments
Exercise

  • Vigorous exercise three to five times per week

All types

  • NNT = 7.4 to prevent a greater than 50-point increase on the IBS Severity Score over 12 weeks18

Fiber

  • Psyllium husk

All types

  • Fiber is ineffective19

Over-the-counter laxatives

  • Polyethylene glycol (Miralax)

Constipation-predominant

  • Improves stool frequency, but not abdominal pain; scant evidence of effectiveness20

Antidiarrheals

  • Loperamide (Imodium)

Diarrhea-predominant

  • Effectively decreases stool frequency and increases stool consistency21

  • Diphenoxylate/atropine (Lomotil) has not been studied for IBS

Probiotics

  • Lactobacillus, Bifidobacterium, Streptococcus

All types

  • NNT = 4 to prevent worsening global IBS symptoms†22,23

Antibiotics

  • Rifaximin (Xifaxan)

Diarrhea-predominant, mixed presentation

  • NNT = 11 to prevent worsening global IBS symptoms over four weeks

  • Neomycin

Constipation-predominant

  • Improves constipation and bloating24,25

Antispasmodics

  • Hyoscyamine (Levsin), dicyclomine (Bentyl)

All types

  • NNT = 7 for improvement of abdominal pain†

  • NNT = 5 for improvement of global assessment

  • NNT = 3 for improvement in symptom score19

Selective C-2 chloride channel activators

  • Lubiprostone (Amitiza)

Constipation-predominant

  • Improves global IBS symptoms26

Antidepressants

  • SSRIs: citalopram (Celexa), fluoxetine (Prozac), paroxetine (Paxil)

  • TCAs: amitriptyline, desipramine (Norpramin), doxepin, imipramine (Tofranil), trimipramine (Surmontil)

All types

  • NNT = 5 for improvement in abdominal pain

  • NNT = 4 for improvement in global assessment

  • NNT = 4 for improvement in symptom score19

Complementary and alternative therapies

  • Psychological treatments, hypnotherapy, acupuncture, herbal therapies, peppermint oil

All types

  • NNT = 4 to prevent persistent IBS symptoms (psychological treatments)†

  • Quality of included trials was inadequate to draw conclusions about hypnotherapy or acupuncture

  • Some herbal therapies may be effective for treating IBS, but trials have inadequate methodology and small sample sizes

  • NNT = 2.5 to improve IBS symptoms (peppermint oil)†27–32

5-HT3 antagonists

  • Alosetron (Lotronex)

Severe diarrhea-predominant (women only)

  • Improves global IBS symptoms and abdominal pain

  • NNT = 7 to improve symptoms†

  • Serious adverse events including ischemic colitis, constipation, and death; restricted use in the United States33

5-HT4 agonists

  • Tegaserod (Zelnorm)

Constipation-predominant

  • NNT = 17 to improve constipation and stool frequency†

  • Serious adverse events including myocardial infarction, unstable angina, and stroke

  • Available only for emergency use through the U.S. Food and Drug Administration34