Hypnosis for Abdominal Pain -- How Do We Know it Works?
After my first training workshop in clinical hypnosis, I didn't fly home from Virginia to California -- I floated. It seemed totally obvious to me that this new/old technique could help many of my patients who were suffering from chronic abdominal pain.
I just knew it.
But in medicine, like in life, things that seem obvious are not always right. "Just knowing it" or having a gut feeling is not enough. We want to see the evidence.
So, what evidence could show that hypnosis really works for kids with abdominal pain?
Actually, I'd seen that evidence already -- evidence which had prompted me to sign up for the workshop in the first place.
It is very difficult, if not impossible, to study hypnosis the same way that one might study a medication. To find out if a drug is effective, the gold standard is a double-blinded, randomized, controlled trial. Some patients receive the study drug, and others receive a "control" intervention, which might be an inactive placebo or the existing standard of care. Neither the patients nor the researchers know who is in the intervention group and who is in the control group.
In a hypnosis study, though, it is hard to have people blinded to the intervention. Most people can tell if they received the hypnosis rather than the placebo. And the team member doing the clinical hypnosis had better be able to tell the difference!
Study in the Netherlands
With that obstacle in mind, a group of researchers in the Netherlands did the next best thing. Their plan was to extend work that had already been done in the adult population. Studies had already demonstrated the effectiveness of hypnosis for adults with irritable bowel syndrome, functional dyspepsia (upper abdominal discomfort), and non-cardiac chest pain.
With the patients’ and parents’ consent, the researchers enrolled 53 patients with chronic abdominal pain, between the ages of 8 and 18. All of them had at least 12 months of GI symptoms and met a strict definition of either "functional abdominal pain" or "irritable bowel syndrome." All of them had been referred to an academic gastroenterology practice at a major medical center, after an initial (unsuccessful) course of treatment by their primary care provider.
Eventually, 28 patients were started in the hypnotherapy (HT) group and another 25 patients were started in the standard medical care (SMC) group (one patient dropped out from each group over the course of the study).
The two groups did not have any significant differences in average age or gender split. They also did not have any differences in their baseline scores for pain intensity, frequency, or associated symptoms including nausea, vomiting, loss of appetite, gassiness, pain overnight or on waking, and pain related to meals.
Over the course of three months, the HT group received six sessions of hypnotherapy, each 50 minutes long. These sessions promoted general relaxation and included personalized hypnotic suggestions for control of abdominal pain, improved gut function, increased confidence, better sleep, and general well-being.
The SMC group received three sessions of supportive therapy, each 30 minutes long, also over the course of three months. These sessions included discussion of recent symptoms and possible triggers. Additionally, the SMC patients received education, dietary advice, fiber supplementation, and use of pain medication or acid blocking medication if needed.
Six times after the start of the study, and lasting for a week each time, patients charted their symptoms daily. They documented the intensity and frequency of any abdominal pain, as well as associated symptoms.
Improvements in Symptoms
Happily, for everyone involved, both groups showed improvements in their symptoms. However, the improvement was dramatically better in the HT group than the SMC group.
Specifically, one year after the end of the sessions, the pain intensity score decreased by 90% in the HT group, while in the SMC group it decreased by 43%. Pain frequency scores decreased by 92% in the HT group, and by 35% in the SMC group. Scores for associated symptoms decreased by 41% in the HT group and 33% in the SMC group. Overall, one year after the end of the treatment, 85% of the patients in the HT group were in remission from their symptoms, compared to only 25% in the SMC group.
The researchers followed up with the same patients several years later -- on average, 4.8 years later. They were able to reach all 27 of the patients in the HT group, and 22 out of the 24 patients in the SMC group. They all filled out the same scoring measures as they had during the initial study.
In both groups, the pain frequency and pain intensity scores were better than they had been initially. However, the HT group was still doing much better than the SMC group. Even with the passage of time, the pain intensity score in the HT group was still 79% below baseline, compared to 45% in the SMC group.
The pain frequency score was 83% lower than baseline in the HT group, compared to 51% below baseline in the SMC group. Overall, 68% of the patients in the HT group were in clinical remission, compared to only 20% in the standard care group.
A treatment which still showed significant effectiveness, almost 5 years after the study was completed? This was evidence which caught my attention. And after my first training workshop, I "just knew it" on an experiential level, as well as a scientific one.
Vlieger AM, Menko-Frankenhuis C, Wolfkamp SC, Tromp E, Benninga MA. Hypnotherapy for children with functional abdominal pain or irritable bowel syndrome: a randomized controlled trial. Gastroenterology. 2007 Nov;133(5):1430-6. doi: 10.1053/j.gastro.2007.08.072. Epub 2007 Sep 2. PMID: 17919634.
Vlieger AM, Rutten JM, Govers AM, Frankenhuis C, Benninga MA. Long-term follow-up of gut-directed hypnotherapy vs. standard care in children with functional abdominal pain or irritable bowel syndrome. Am J Gastroenterol. 2012 Apr;107(4):627-31. doi: 10.1038/ajg.2011.487. Epub 2012 Feb 7. PMID: 22310221.