Study designs of evaluations included in the review
Any type of study design, with the exception of single case and expert opinion, were eligible.
Specific interventions included in the review
Studies using single-component hypnotherapy were eligible; multiple component therapies were excluded. Gut-directed hypnotherapy (GDH) was performed via audiotape or as individual GDH in 4 to 12 sessions of 30 to 90 minutes each. Control therapies, where used, included supportive psychotherapy, symptom monitoring and usual general practice management.
Participants included in the review
Studies of adult patients with IBS, irrespective of diagnostic criteria, were eligible for inclusion. The included studies were of patients refractory to conventional treatment, classical or atypical IBS, IBS not otherwise specified, and long-term IBS sufferers known to the service.
Outcomes assessed in the review
Studies of any patient-related outcome were eligible for inclusion. The outcomes extracted included various types of symptom scores, overall improvement or well-being, consultation rate and mediation use, physiological or emotional measures, and quality of life. Most of the studies used a symptom score outcome that included abdominal pain, distension and altered bowel habit. Follow-up beyond the treatment period ranged from 5 months to 6 years. One study carried on a 12 month follow-up for both the intervention and control groups, while the other studies followed up either the intervention group or the control group.
How were decisions on the relevance of primary studies made?
Two authors independently reviewed all citations, using predetermined criteria, to identify potentially relevant trials.