Irritable Bowel Syndrome: Drug Therapy

Therapy target

  • Improvement of the IBS symptomatology

Therapy recommendations

Improvement of IBS symptoms is best done with counseling of the patient and a change in diet including intake of probiotics (according to S3 guideline: level of evidence A, strength of recommendation ↑, strong consensus). Drug therapy should be symptom-oriented and used only for a short time. An attempt at drug therapy without response should be discontinued after no more than (!) 3 months. The following principles should be observed:

  • Therapy is based on the predominant symptoms.
  • Diarrhea (diarrhea):
    • Tricyclic antidepressants used to treat IBS symptoms (diarrhea, pain) should be used below the usual dose for an antidepressant effect. [Level of evidence A, strength of recommendation ↑↑↑, strong consensus]
    • For diarrhea, loperamide, dietary fiber, colestyramine, probiotics (dietary supplements containing probiotic cultures), phytotherapeutics, or, in isolated cases, a 5-HT3 antagonist can be used.
    • Treatment of diarrhea with probiotics (dietary supplements with probiotic cultures), may be performed. [Level of evidence A, strength of recommendation ↑, strong consensus.]
    • Soluble fiber can be used to treat diarrhea in diarrhea-dominant IBS. [Grade of recommendation 0, strong consensus]
    • Treatment of diarrhea with antibiotics should be avoided rather. [Level of evidence C, strength of recommendation ↓, strong consensus]
    • Probiotics may be tried in children, especially in cases of postenteritic genesis of IBS or predominant diarrhea. [Level of evidence B, strength of recommendation ↑, consensus]
  • Constipation (constipation):
    • Tricyclic antidepressants should not be prescribed for constipation-type IBS (“constipation type”). [Level of evidence A, strength of recommendation ↓↓, consensus]
    • Serotonin reuptake inhibitors (SSRIs) may be used for IBS obturation, particularly in the presence of foreground pain and/or psychological comorbidity [Level of evidence B, strength of recommendation ↑, consensus]
    • Macrogol-type osmotic laxatives can be given for IBS-O. [Grade of recommendation A, strong consensus]
    • Dietary fiber in the form of the water-soluble gelling agents such as psyllium husks (psyllium; 2-6 x daily 1 scoop or 1 sachet; each with 150 ml of water; ensure adequate hydration) should be tried in RDS-O. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • For constipation, osmotic and stimulant laxatives (laxatives), lubiprostone, probiotics (dietary supplements containing probiotic cultures), spasmolytics (antispasmodic drugs), or phytotherapeutics (mixture STW-5) can be used. A trial of prucalopride (serotonin receptor agonist) can be made in refractory cases.
    • Spasmolytics may also be used to treat patients with IBS-O. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • Probiotics can be tried in patients with IBS-O. [Level of evidence A, strength of recommendation ↑, strong consensus] Instead of tricyclic antidepressants, serotonin reuptake inhibitors (SSRIs) should be used when indicated. Other psychoactive substances should not be used.
    • Nonabsorbable antibiotics (eg, rifaximin, neomycin) should tend not to be given in patients with RDS-O. [Level of evidence A, strength of recommendation ↓, consensus]
  • Abdominal pain:
    • Treatment of pain with peripheral analgesics/pain relievers (acetylsalicylic acid (ASA), acetaminophen, NSAIDs (nonsteroidal anti-inflammatory drugs), metamizole) should not be performed.
    • Therapy for pain with spasmolytics (antispasmodic drugs) should be. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • Tricyclic antidepressants can be used to treat pain in adults. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • Treatment of pain with soluble fiber can be performed. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • SSRIs can be used to treat pain in adults. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • For treatment of pain, 5-HT3 antagonists (eg, alosetron) may be given in individual cases.[Level of evidence A, strength of recommendation ↑, consensus]
    • Treatment of pain with probiotics (dietary supplements containing probiotic cultures), can be performed [Level of evidence A, strength of recommendation ↑, strong consensus]
    • For pain, spasmolytics, tricyclic antidepressants, SSRIs, fiber, or probiotics can be used. Phytotherapeutics may also be used. Analgesics should not be used.
    • Therapy of pain with antibiotics should rather not be performed. [Level of evidence A, strength of recommendation ↓, consensus]
  • Flatulence/abdominal distension/flatulence:
    • SSRIs should rather not be used to treat flatulence/meteorism. [Level of evidence B, strength of recommendation ↓, consensus.]
    • Effective drug therapy for constipation or diarrhea in the IBS patient may also improve symptoms from the bloating/abdominal distension (expansion or overdistension)/meteorism/flatulence (“winds”) symptom domain. [Level of evidence A, strength of recommendation ↑, strong consensus]
    • Therapy with probiotics (dietary supplements containing probiotic cultures), may result in improvement of flatulence/abdominal distension/meteorism/flatulence. [Level of evidence B, strength of recommendation ↑, strong consensus.]
    • Cholinergics/parasympathetic mimetics should not be prescribed for the treatment of flatulence/abdominal distension/meteorism/flatulence. [Level of evidence A, strength of recommendation ↓, strong consensus]
    • Therapy with the nonabsorbable antibiotic rifaximin may be attempted in refractory cases for the treatment of bloating/abdominal distension/meteorism/flatulence. [Level of evidence A, strength of recommendation ↑, consensus]
    • Therapy of bloating/abdominal distension/meteorism/flatulence with pancreatic enzymes should not be attempted in IBS. [Level of evidence D, strength of recommendation ↓↓↓, strong consensus]
    • Analgesics should not be given to treat bloating/abdominal distension/meteorism/flatulence. [Level of evidence B, strength of recommendation ↓, strong consensus]
  • Antidepressants (drugs used to treat depression) may be prescribed in the presence of mental comorbidity/co-morbidity (depression, anxiety disorders). [Level of evidence A, strength of recommendation ↑, strong consensus]
  • See also under “Other therapy.”

General notes

  • Prebiotics: No recommendation can be made in this regard for the treatment of irritable bowel syndrome.
  • Probiotics: Selected probiotics can be used: Choice of strain according to the symptomatology (according to S3 guideline).
  • Phytotherapeutics can be tried

Other agents.

There is evidence that the topical antibiotic rifaximin (duration: 2-3 times daily, 1-2 weeks, 1-2 tbl à 200 mg; therapy can be repeated in cycles if necessary) can reduce the symptoms (gas formation and abdominal discomfort) of IBS without constipation. Note: Should only be used if there is a confirmed bacterial overgrowth in the small intestine (bacterial overgrowth syndrome; dysbiosis) and other therapeutic measures have been unsuccessful!

Agents that should not be used in irritable bowel syndrome

The following agents should not be used in irritable bowel syndrome with diarrhea:

  • Antibiotics
  • Aloe vera
  • Racecadotril
  • TCM herbal therapy

The following agents should not be used in irritable bowel syndrome with constipation:

  • Domperidone
  • Non-absorbable antibiotics

The following agents should not be used in IBS with pain:

  • Aloe vera
  • Analgesics (paracetamol, NSAIDs, metamizole)
  • Amitriptyline should not be used in children/adolescents
  • Antibiotics
  • Opioid analgesics
  • Μ-Opioid agonists
  • Pregabalin/Gabapentin
  • Pancreatic enzymes

The following agents should not be used in IBS with bloating/abdominal distension/flatulence:

  • Analgesics/pain relievers (acetaminophen, NSAIDs, metamizole).
  • Antihistamines
  • Cholinergics/parasympathomimetics
  • Defoaming substances (simeticon, dimeticon).

Phytotherapeutics

Positively affect the intestine in irritable bowel syndrome:

  • Peppermint (peppermint oil) – effective for treating especially IBS symptoms “pain” and “flatulence”.
  • Anise
  • Fennel
  • Chamomile
  • Caraway seeds – as hot caraway pads.
  • Turmeric
  • Melissa
  • Ribbon flower

Active ingredients used in combination for irritable bowel syndrome include peppermint oil and caraway oil.

Supplements (dietary supplements; vital substances)

Suitable dietary supplements should contain the following vital substances:

A typical representative of probiotics are lactobacilli. These are lactic acid bacteria that can break down sugar to lactic acid. They occur naturally in the human intestine. Patients suffering from irritable bowel syndrome (IBS) benefit from taking lactobacilli. They displace gas-forming bacteria. The prescription of probiotics have a level of evidence A with strong consensus!