Constipation may be caused by the progress of the cancer itself, as when tumors invade the gastrointestinal tract, or by other related factors such as prolonged periods of confinement to bed without exercise. Certain chemotherapeutic drugs, notably vincristine (Oncovin) and vinblastine (Velban), can slow down or temporarily immobilize the peristaltic action of the bowel, which moves waste through the intestines. Narcotics, anticonvulsants, antidepressants, tranquilizers, and muscle relaxants are other agents that can cause decreased peristalsis.
Constipation can also result from inadequate intake of food, dehydration, inadequate roughage in the diet, or the psychological impact of cancer—anxiety and depression.
To prevent constipation, the person should:
- Respond immediately to the urge to defecate, preferably in a private environment that reduces distraction.
- Increase the amount of high-fiber foods in the diet. Fiber increases the volume of the stool, makes it softer by increasing the amount of water retained in it, and causes it to pass through the bowel more rapidly, decreasing the occurrence of an impacted bowel. High-fiber foods include whole-grain products, bran, fresh raw fruits with skins and seeds, fresh raw vegetables, nuts, coconut, corn, popcorn, raisins, dates, prunes, and prune juice.
- Avoid cheese products and refined grain products.
- Drink at least eight to ten glasses of fluid a day. Fresh fruit juices and warm or hot liquid upon arising are especially helpful.
- Try to get as much physical activity as can be tolerated. This facilitates the passage of feces through the intestine.
- Use a stool softener such as Colace or Metamucil daily. This is especially important for patients receiving vincristine (Oncovin), vinblastine (Velban), or opiate narcotic analgesics. With a cellulose, bulk-producing drug such as Metamucil, fluid intake often glasses a day is especially important.