Irritable bowel syndrome and functional constipation management with integrative medicine: A systematic review

ARTICLE HIGHLIGHTS

Research background

Irritable bowel syndrome (IBS) and functional constipation (FC), two representative functional gastrointestinal disorders, are commonly encountered in daily clinical practice. In the outpatient setting, patients with IBS and FC account for 45.1% and 14.7% of all functional gastrointestinal disorder (FGID) patients, respectively. Nevertheless, the pathophysiologies of IBS and FC are still unclear, and the current interventions mostly address symptoms. Hence, in China, many clinicians consider integrating traditional Chinese medicine (TCM) into disease management. The effectiveness of TCM has been demonstrated through clinical experience and modern research, while the integration of Western medicine (WM) and TCM is still debated due to the unique medical system and various interventions involved in TCM. This systematic review is an innovative attempt to comprehensively summarize the recommendations with strong evidence in clinical practice guidelines (CPGs), aiming to identify the issues that might be addressed via integrative medicine (IM) and to provide new insights into future research.

Research motivation

The fundamental purpose of IM is to obtain synergistic therapeutic effects by combining two medical systems, namely, WM and TCM. In clinical practice, it is still difficult for doctors to identify the most suitable interventions and their timing. CPGs are systematically developed medical statements that contain the currently available and generally accepted interventions accompanied by the corresponding recommendations. By identifying the strong evidence-based (EB) recommendations in the CPGs, clinicians can not only have a better understanding of the current management of IBS and FC but also recognize clinical questions that have potential in further IM research.

Research objectives

The fundamental objective of this study was to systematically review the currently available CPGs and summarize the WM and TCM interventions that have strong evidence. More importantly, based on the available evidence, doctors and researchers can discover clinical issues that could be addressed with IM and then design relevant studies to verify the application.

Research methods

Seven databases, namely, PUBMED, Cochrane Library, EMBASE, the Chinese Biomedical Literature Database (SinoMed), the Chinese Scientific Journal Database, China National Knowledge Infrastructure, and the Wanfang database, were selected. The search terms were “clinical practice guideline”, “medical statement”, “expert consensus”, “irritable bowel syndrome”, “functional constipation”, and the corresponding synonyms. In addition, the official websites of national health institutions and handbooks were selected as supplementary resources. The extracted information included the initiating organization, title, year of publication, definitions of diseases, and details of the recommendations. According to the method of development of the CPGs, the included records were classified into EB guidelines, consensus-based (CB) guidelines, and consensus-based guidelines with no comprehensive consideration of the EB (CB-EB) guidelines. In addition, based on the quality of evidence, the strength of the recommendations related to the interventions was translated into a 4-grade system as follows: strong recommendation, recommendation, weak evidence, and insufficient evidence.

Research results

A total of 30 CPGs were included in the systematic review, including 16 IBS CPGs, 10 FC CPGs, and 4 CPGs for both. In general, most WM CPGs were developed as EB guidelines, while all TCM CPGs and most IM CPGs were CB guidelines. For IBS, antispasmodics and peppermint oil for pain, loperamide for diarrhea, and linaclotide for constipation had relatively high recommendation levels. Psyllium as a bulking agent, polyethylene glycol and lactulose as osmotic laxatives, bisacodyl and sodium picosulfate as stimulant laxatives, lubiprostone and linaclotide as prosecretory agents, and prucalopride were supported by relatively strong clinical evidence. TCM interventions were generally recommended based on expert consensus, which limited the recommendation level to weak or insufficient. For IBS, “liver depression and spleen deficiency” for diarrhea, “liver depression and qi stagnation” for constipation, and “cold-heat complex” for mixed type were the generally accepted patterns. The corresponding TCM formulas were the Tongxieyao formula, Liumo decoction, and Wumei pills, respectively. For FC, four patterns were generally acknowledged: intestinal excess heat, intestinal qi stagnation, dual deficiency of the lung and spleen, and spleen-kidney yang deficiency. Correspondingly, the specific formulas were Maziren pills, Liumo decoction, Huangqi decoction, and Jichuan decoction, respectively. The majority of TCM and IM CPGs recommended acupuncture therapy. For IBS-D, the primary acupoints included Zusanli (ST36), Tianshu (ST25), and Sanyinjiao (SP6). For IBS-C and FC, the primary acupoints included Dachangshu (BL25), Tianshu (ST25), Zhigou (SJ6), and Fenglong (ST40).

Research conclusions

This systematic review innovatively summarize the CPGs regarding both TCM and WM over the last 30 years, providing a comprehensive picture of the current management of IBS and FC. The results were generated from generally acknowledged CPGs, which guarantees high levels of confidence in and clinical practicality of the conclusions. According to the results, relatively comprehensive management algorithms for IBS and FC have been established. For IBS, patients manifest with different predominant symptoms, and they are treated with antispasmodics and peppermint oil for pain, loperamide for diarrhea, and linaclotide for constipation. For FC patients, empiric agents such as fiber supplements and osmotic laxatives are administered first. If an inadequate response occurs, relatively aggressive interventions such as stimulant laxatives and prosecretory agents are considered after excluding defecatory disorder. However, there are still gaps in management that could be filled by TCM. For instance, herbal medicines could be considered as alternatives or used in combination when first-line medications are not effective enough. In addition, TCM external interventions could be applied when patients refuse pharmacological treatment or are concerned about herb-drug interactions. Nevertheless, to validate these findings, it is still necessary to conduct rigorous high-quality clinical studies to establish strong clinical evidence.

Research perspectives

Based on the CPGs generated in recent decades, both WM and TCM have relatively comprehensive algorithms for IBS and FC treatment. The application of IM is promising in certain aspects of IBS and FC management. Future attention should be paid to the establishment of high-quality IM evidence, which would not only facilitate the management of IBS and FC but also serve as a template for IM application in common clinical diseases.