The present study reported a comparison between two treatment modalities for neuromuscular training of patients experiencing dyssynergic defecation. The prominent complaint of the patients was straining and incomplete evacuation, with slow-transit constipation found in only 5% of cases.
Although both training methods had positive effects on patient outcomes, the comparative efficacy of biofeedback was highly superior to balloon-assisted neuromuscular training with respect to the quantitative variables of time and suitable volume of balloon evacuation. Although the treatment sessions were repeated six times in both groups, the differences can be explained, in part, by the need for repetitive balloon evacuation training at home, which may not have been as simple for some patients as others. We are aware of the limitations to and biases inherent in open-label studies; however, maximal efforts were made to keep the quality of the study in the present form.
Theoretically, neuromuscular training was included in both arms of the study; biofeedback-assisted training was based mostly on auditory and visual biofeedback to maintain better coordination of muscles, while balloon-assisted training was based on sensory biofeedback with the use of a stool-like device to stimulate appropriate defecation.
Wiesel et al (
11), Chiotakakou-Faliakou et al (
12) and Emmanuel and Kamm (
13), in three separate but uncontrolled trials, used biofeedback for similar patients. Patients in the study by Chiotakakou-Faliakou et al (
12) reported a sense of well-being following biofeedback. The ratio of Wiesel et al’s (
11) cases was 79%, and more than one-half of the group studied by Emmanuel and Kamm (
13) reported more frequent bowel movements each week. Patient satisfaction with the treatment seemed to be high in our study, both in the entire sample and in each group. Our results were similar to those of Bleijenberg and Kuijpers (
14), who divided patients into two similar trial arms, although the number of the cases (two groups of 11 patients) was lower than in our study, and also demonstrated a superior efficacy of biofeedback (
14).
In contrast to these reports, Koutsomanis et al (
15) compared muscular training with biofeedback and found no significant difference, but finally recommended and insisted on muscular training for these patients.
Interestingly, in some studies, recruited patients were not included merely based on criteria of dyssynergic defecation but on criteria of constipation as a whole, with these nonhomogeneous groups of patients subsequently assigned to biofeedback. For example, the 55 good outcomes reported by Chiotakakou-Faliakou et al (
12) were based on patients with constipation; however, in the study by Dailianas et al (
16), only 30% of the patients could be classified as having dyssynergic defecation, with only 30% of these patients having an acceptable outcome.
Another important aspect of neuromuscular training is the longevity of treatment effects, especially given the long duration of patient complaints and symptoms before starting treatment. For example, Chiarioni et al (
17) followed patients for 24 months and established a persistent effect of biofeedback at 71%. Battaglia et al (
7) also showed a remnant efficacy of greater than 50% after one year. We could not follow-up on our patients and cannot reliably comment on the stability of our intervention over time; however, we recommend the use of electromyographic biofeedback with auditory and visual outputs, although it requires well-trained personnel and an adequately equipped clinical setting.