Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 513

The physical examination is directed to identifying underlying medical causes for constipation, excluding faecal impaction, and providing a preliminary assessment of anorectal function. A faecal mass may be palpable on abdominal palpation.

Rectal examination includes inspection of the perineum at rest and with strain. Normal perineal descent during strain is 1–4 cm. No perineal descent suggests a failure of the pelvic floor to relax and allow the passage of stool. Excessive perineal descent, sometimes characterized as a ballooning of the perineum, indicates excess laxity to the pelvic floor musculature and dyssynergic defecation. This finding is most common in multiparous women. The strength of the anal sphincter muscle at rest and with squeeze is assessed. Puborectalis and anal sphincter relaxation during strain provide a measure of proper of the appropriateness of pelvic floor function. Failure of relaxation or very high anal sphincter resting pressure suggests dyssynergic defecation. The presence of weak anal sphincter pressures may place the patient at risk for incontinence during treatment of the constipation.

Rectal prolapse can be associated with difficult evacuation due to blockage of the anal canal with the rectum. These patients usually also described episodes of bowel incontinence. A more severe rectal prolapse can be identified during strain in the left lateral decubitus position. A better way to assess for rectal prolapse is to have the patient strain over a commode. The examiner places a gloved hand below the anus and can feel the rectal prolapse descend and touch the glove. The degree of rectal prolapse can be assessed by visual inspection. The physical examination, including rectal examination, is a necessary part of the evaluation of any constipated patient.