Drug therapy reviews: pharmacotherapy of diarrhea.

Gastrointestinal physiology, and the pathophysiology, diagnosis, symptoms and treatment of acute and chronic diarrhea are reviewed. Drugs used in the treatment of diarrhea include opiates (morphine, codeine), synthetic anti-diarrheals (diphenoxylate, loperamide), anticholinergics (atropine, propantheline), adsorbents (kaolin, pectin, cholestyramine resin) and Lactobacillus acidophilus. Chronic diarrhea and acute diarrhea caused by microorgansims, drugs and viruses are described. The management of diarrhea can be divided into three categories: (1) supportive therapy (fluid and electrolyte replacement); (2) symptomatic therapy which improves the consistency of the stool and reduces the frequency of bowel movements; and (3) specific therapy aimed at treating the cause (e.g., antibiotics for bacteria-induced diarrhea) or blocking the cellular mechanisms of fluid and electrolyte loss. Most acute diarrheal conditions can be managed successfully by avoiding oral solids and ingesting carbohydrate-electrolyte solutions. Synthetic antidiarrheals may increase the toxicity associated with bacterial diahhrea.

Use and abuse of laxatives.

Colon physiology, the causes of constipation, an approach to management of constipation, and the features of various laxatives are reviewed. The categories of individual agents discussed include the bulk-forming laxatives, stimulant cathartics, saline laxatives, hyperosmotic laxatives, surfactant laxatives, emollient laxatives, enemas and suppositories. Dietary change and attention to proper bowel habits are frequently the only therapy necessary for the treatment of constipation. When laxative intervention is necessary, one of the milder agents should be employed over a short period of time. The chronic abuse of stimulant cathartics, often deeply rooted in family or ethnic traditions, is a significant problem and difficult to treat.