Leuprolide acetate, a gonadotropin-releasing hormone (GnRH) analogue, has been investigated as a treatment for irritable bowel syndrome (IBS) because of the predominance of IBS in women and the exacerbation of symptoms reported during menses. Symptoms of abdominal pain, nausea, vomiting, bloating, and early satiety were improved with the administration of the drug. However, studies were small and enrolled women were diagnosed with functional bowel disorder, which includes IBS as well as additional gastrointestinal (GI) disorders. Thus, with its efficacy based on limited data and a side effect profile that includes hot flashes, headache, and depression, the use of leuprolide may be limited.
Herbal medicine has traditionally been used for the treatment of GI disorders in China. Recently, a randomized, double-blind 16-week study in patients with irritable bowel syndrome (IBS) compared the efficacy of a standard herbal preparation and an individualized herbal preparation to placebo. Patients receiving the herbal preparations reported improvement in symptoms and quality of life. In a follow-up assessment 14 weeks after completion of the trial, only patients treated with the individualized herbal formulation had maintained improvement. The herbal preparation contained at least 20 different ingredients, and the study has been criticized by Western clinicians due to the lack of a commercial product containing the exact same formulation. Therefore, the clinical utility of this herbal preparation is questionable.
As previously discussed, the discovery of serotonin (5-HT) receptor subtypes has led to a better understanding of irritable bowel syndrome (IBS) as well as development of potential therapies.