Fifty-three studies were included.
Only 15 of the included studies were of good quality (a Jadad score of at least 3 out of 5). Forty studies had insufficient power to detect even a large effect size (i.e. fewer than 25 patients in each group).
Two out of 4 studies in adults reported a significant benefit with biofeedback compared with no biofeedback, although both were of a poor quality. Seven studies in children showed no benefit (5 were of a poor quality). Six studies with some form of biofeedback in all treatment groups reported mixed results.
Six out of 7 studies reported benefit with hypnosis compared with no hypnosis. One study showed some benefit with hypnotherapy compared to an audiotape. All were of a poor quality.
Six out of 8 studies reported a benefit of relaxation therapy compared with no relaxation therapy. All except one study were of a poor quality.
All 8 studies of behavioural therapy reported a benefit compared with no behavioural therapy (6 studies; 4 of a poor quality) or other interventions or standard care (2 studies; one of good quality, Jadad score 4).
Four studies reported a significant benefit with cognitive therapy versus no cognitive therapy. Three studies were of a poor quality.
One of 2 studies reported a significant benefit with guided imagery compared with no guided imagery. Both studies were rated as good quality (Jadad score 3).
One study of placebo therapy (rather than placebo control) was included. It showed no significant benefit compared with medication in diverticular disease. The quality of this study was rated as good (Jadad score 3).
Various multimodal therapies were tested in 5 studies. Their findings were described in detail in the report.