Table of Contents

Chapter 3: Maximizing Quality of Life After Initial Treatment

b. Bowel Dysfunction

The broad term of bowel dysfunction includes diarrhea or frequent stools; fecal incontinence or the inability to control bowel movements; and rectal bleeding. By far, all of these side effects are more common following external beam radiotherapy than any other primary therapy, but as techniques and dose planning strategies improve, even these rates have been dropping.

If you recall from the anatomy lesson in Chapter 2, the prostate presses up against the rectal wall. During prostatectomy, damage to the rectum is rare, and the bowel changes seen in the first few weeks following surgery are more likely the result of the body adjusting to the increased abdominal space with the loss of the prostate. Radiation therapy, however, can cause significant damage to the rectum, resulting in any and all of the symptoms listed above.

Standard external beam radiotherapy blankets a wide area with radiation. Not surprisingly, the highest rates of bowel dysfunction are seen with this type of therapy. In addition, bowel function tends to remain the same or deteriorate rather than improve over time as the effects of radiation accumulate. After two years, about 10% of men reported having persistent diarrhea a few times each week, while rectal bleeding increased steadily from 5% immediately after treatment to 25% after two years.

Rates with 3-D conformal radiation therapy are considerably lower, but they, too, increase over time, and, after two years, are similar to those seen with standard external beam radiotherapy. By contrast, after two years, the rates with intensity-modulated radiation therapy (IMRT) remain low, hovering around 5%. Bowel dysfunction following brachytherapy tends to be lower than that seen with external beam radiotherapy, and, most importantly, seems to stabilize at a low rate after just one year. (See Chapter 2 for more detailed information about radiation therapy for initial treatment.)

As techniques improve and dose planning becomes more sophisticated, it’s likely that the rates of long-term bowel side effects will go even lower. In the meantime, as with all other side effects, much depends on practitioner skill, so be sure to select a doctor who possesses the experience and skill to spare the rectal tissue as much as possible.

Short of treating the individual symptoms as needed, there are few, if any, treatment options for bowel dysfunction following radiation therapy. Careful monitoring of the diet to avoid foods that might irritate the gastrointestinal tract is important, but complete elimination of fibrous, bulky foods can lead to constipation and straining, which in turn can exacerbate rectal bleeding. Working with your doctors and nurses as well as with a nutritionist can help you identify which foods might help promote bowel healing while minimizing irritation and further problems.