On September 16, the journal Gastroenterology published online the Guidelines for the Pharmacologic Treatment of Irritable Bowel Syndrome, developed by the American Gastroenterological Association (AGA). The guidelines provide nine recommendations for the pharmacologic treatment of irritable bowel syndrome (IBS) based on rigorous research evidence for the pharmacologic treatment of IBS, but non-pharmacologic treatments, including dietary and lifestyle changes, are not considered. This edition captures the core contents of the guidelines and invites Professor Hou Xiaohua from the Department of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology to share with readers his comments on the guidelines.
Introduction to the guideline: IBS drug treatment recommendations
Q1. Should linaclotide be used in patients with constipated irritable bowel syndrome (IBS-C)?
The American Gastroenterological Association (AGA) recommends linaclotide (over no drug therapy) in patients with IBS-C (strong recommendation, high quality evidence).
Q2. Should lubiprostone be used in patients with IBS-C?
The AGA recommends lubiprostone in patients with IBS-C (better than no drug therapy) (conditional recommendation, moderate quality evidence).
Q3. Should polyethylene glycol (PEG) light laxatives be used in patients with IBS-C?
AGA recommends the use of light laxatives (superior to no drug therapy) in patients with IBS-C (conditional recommendation, low quality evidence).
Q4. Should rifaximin be used in patients with diarrheal IBS (IBS-D)?
AGA recommends rifaximin in patients with IBS-D (superior to no drug therapy) (conditional recommendation, moderate quality evidence).
Q5. Should alosetron be used in patients with IBS-D?
AGA recommends the use of alosetron in patients with IBS-D to improve overall symptoms (better than no medication) (conditional recommendation, moderate quality evidence).
Q6. Should loperamide be used in patients with IBS-D?
AGA recommends loperamide (better than no medication) in patients with IBS-D (conditional recommendation, very low quality evidence).
Q7. Should tricyclic antidepressants be used in patients with IBS?
AGA recommends the use of tricyclic antidepressants (better than no medication) in patients with IBS (conditional recommendation, low quality evidence).
Q8. Should selective 5-hydroxytryptamine reuptake inhibitors (SSRIs) be used in patients with IBS?
AGA does not recommend SSRIs in patients with IBS (conditional recommendation, low quality evidence).
Q9. Should antispasmodics be used in patients with IBS?
AGA recommends the use of antispasmodics (better than no medication) in patients with IBS (conditional recommendation, low quality evidence).
Expert commentary: Improving IBS treatment with evidence
With the accelerated pace of life and changes in the social environment, the incidence of irritable bowel syndrome (IBS) has a tendency to gradually increase. Due to the diversity and complexity of the pathogenesis, IBS is recurrent and difficult to cure, and patients frequently seek medical care and have reduced quality of life, which seriously affects their mental and physical health.
The American Gastroenterological Association (AGA) has recently released this guideline on the pharmacological treatment of IBS, which is concise and evidence-based. It starts from the main clinical symptoms of IBS and evaluates the effectiveness of nine new or old drugs in the treatment of IBS, providing a good basis for the clinical pharmacological treatment of IBS.
The two pro-secretory drugs recommended in this guideline, linaclotide and lubiprostone, are both approved by the U.S. Food and Drug Administration (FDA) for the treatment of chronic constipation and constipated IBS (IBS-C).
Linaclotide significantly improves abdominal pain, constipation and overall symptoms in IBS patients by stimulating intestinal fluid secretion, intestinal motility and increasing pain threshold through elevating intracellular and extracellular cyclic guanosine phosphate (cGMP). Phase III clinical trials are currently underway in China.
Lubiprostone is effective in relieving constipation, but the improvement of symptoms such as abdominal pain and voluntary bowel motility is unclear, and the FDA has only approved it for use in female IBS-C patients because the majority of clinical study data is from women.
Polyethylene glycol is an older drug commonly used in clinical practice, which increases intestinal fluid secretion and stool frequency by increasing intestinal luminal osmotic pressure, but does not relieve abdominal pain symptoms. patients.
The guideline clearly recommends rifaximin, an oral non-absorbable antibiotic, for the treatment of patients with diarrheal IBS (IBS-D). Although rifaximin has not been approved by the FDA for the treatment of IBS-D, much evidence suggests that short-term use does have beneficial effects on improving stool firmness, bloating, abdominal pain, and overall symptoms, the exact mechanism of which needs to be further elucidated.
Although loperamide is not effective in relieving abdominal pain, bloating, and systemic symptoms of IBS, it is an effective agent for the treatment of diarrhea and is recommended for IBS-D in the low evidence level of the guidelines. However, due to the potential for serious complications such as constipation and colonic ischemia, the application must be weighed against the benefits.
The guideline recommends tricyclic antidepressants over selective 5-HT reuptake inhibitors (SSRIs) for IBS treatment. Tricyclic antidepressants are effective in relieving systemic symptoms of IBS and in reducing abdominal pain, even in patients with IBS without anxiety or depression.
Antispasmodics are commonly used in the treatment of IBS, and the guidelines suggest that these drugs can provide short-term relief of abdominal pain and discomfort. More commonly used are selective intestinal smooth muscle calcium channel antagonists, such as pivelbromine and octreotide, or the ion channel modulator trimebutine maleate, all of which have a good safety profile.
The American Gastroenterological Association’s IBS drug treatment guideline opinion is for Western IBS patients, which is a necessary reference for clinical decision making in China, but we should also have our own large sample, high-quality research evidence and treatment guidelines applicable to the national population, which especially requires our own research work.
Furthermore, in addition to pharmacotherapy, IBS treatment needs to consider.
① The principle of individualized treatment, each patient has a different response to drugs;
② Exploration of other therapeutic agents, such as probiotics;
③ Not only drugs, but also therapeutic measures such as psycho-behavioral, health support, diet modification and lifestyle modification should be considered.