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Chapter 040. Diarrhea and Constipation (Part 15)

Approach to the Patient: Constipation A careful history should explore the patient's symptoms and confirm whether he or she is indeed constipated based on frequency (e.g., fewer than three bowel movements per week), consistency (lumpy/hard), excessive straining, prolonged defecation time, or need to support the perineum or digitate the anorectum. In the vast majority of cases (probably 90%), there is no underlying cause (e.g., cancer, depression, or hypothyroidism), and constipation responds to ample hydration, exercise, and supplementation of dietary fiber (15–25 g/d). A good diet and medication history and attention to psychosocial issues are key. Physical examination and, particularly,. | Chapter 040. Diarrhea and Constipation Part 15 Approach to the Patient Constipation A careful history should explore the patient s symptoms and confirm whether he or she is indeed constipated based on frequency e.g. fewer than three bowel movements per week consistency lumpy hard excessive straining prolonged defecation time or need to support the perineum or digitate the anorectum. In the vast majority of cases probably 90 there is no underlying cause e.g. cancer depression or hypothyroidism and constipation responds to ample hydration exercise and supplementation of dietary fiber 15-25 g d . A good diet and medication history and attention to psychosocial issues are key. Physical examination and particularly a rectal examination should exclude fecal impaction and most of the important diseases that present with constipation and possibly indicate features suggesting an evacuation disorder e.g. high anal sphincter tone . The presence of weight loss rectal bleeding or anemia with constipation mandates either flexible sigmoidoscopy plus barium enema or colonoscopy alone particularly in patients 40 years to exclude structural diseases such as cancer or strictures. Colonoscopy alone is most cost effective in this setting since it provides an opportunity to biopsy mucosal lesions perform polypectomy or dilate strictures. Barium enema has advantages over colonoscopy in the patient with isolated constipation since it is less costly and identifies colonic dilatation and all significant mucosal lesions or strictures that are likely to present with constipation. Melanosis coli or pigmentation of the colon mucosa indicates the use of anthraquinone laxatives such as cascara or senna however this is usually apparent from a careful history. An unexpected disorder such as megacolon or cathartic colon may also be detected by colonic radiographs. Measurement of serum calcium potassium and thyroid-stimulating hormone levels will identify rare patients with metabolic disorders. .