For constant worriers--how to commune joyfully with your bowels. Unlike other recent books concerned with disorders of the digestive system, this has a salutary emphasis on prevention; the turnoff is the authors' conviction that toilet time can be one of the highlights of the day. Their aim, they announce, is to help us maintain a healthy gastrointestinal system through ""proper diet, exercise, effective toilet postures and activities and cleansing techniques."" (They will also, they note, ""discuss personal experiences that are relevant to an understanding of the issues."") In covering the more common problems--constipation, diarrhea, flatulence, hemorrhoids, and miscellaneous conditions from anal itch to bowel cancer--Ehrlich and Wolf explore not only traditional medical treatments but also alternative therapies, such as exercise and special foods (an appendix of recipes and herbal formulas is included). But because they don't always have the basics quite right, one hesitates to rely on their more unusual suggestions. Exercises for the abdomen (supine leg lifts) can seriously strain the back if done as prescribed here; the recommended use of occasional enemas is questionable at best; and some of the practices advised (like spending recreational amounts of time sitting on the toilet) have been implicated in causing the very problems (in this case, hemorrhoids) they seek to avoid. Most readers will Fund that Robert Holt's more reliable and balanced Hemorrhoids (1979, p. 1462) tells them all they need to know without making overmuch of it.