Constipation Constipation means being unable to move your bowels, having to push harder to move your bowels, or moving them less often than usual. Constipation happens when you get less exercise, or when you eat and drink less than usual. Some medicines cause constipation. Constipation and Chemotherapy Be sure to drink plenty of fluids to help loosen the bowels. If you do not have mouth sores, try warm and hot fluids, including water, to help provide relief from constipation symptoms. Nutritional Management of Constipation During Cancer Treatment Check with your doctor to see if you can increase the fiber in your diet. If you can, try foods like whole-grain breads and cereals, dried fruits, wheat bran, and wheat germ; fresh fruits and vegetables; and dried beans and peas.