The role of manometry, electromyography and radiology in the assessment of faecal incontinence.

The results of laboratory investigations in 156 patients presenting with faecal incontinence are reviewed to see if and how these investigations supplement a careful clinical evaluation, and in particular to see if they help in the practical management of the problem. All patients underwent anal manometry, and in addition 52 underwent anal sphincter electromyography and 27 defaecatory proctography. Anal manometry quantified sphincteric weakness, and proved superior to digital assessment in this regard. Resting and squeeze pressures were less in those with complete than those with partial incontinence but the differences were not statistically significant. The measurements of rectal sensation and compliance were not additionally helpful. Single fibre electromyography provided the best measure of denervation with re-innervation and was abnormal in about 85% of the group studied. Jitter studies were unhelpful. Most patients had some abnormality on defaecatory proctography but clinical significance could not be established. The choice of treatment was made on clinical grounds and was not influenced by these investigations.