Try increasing your intake of whole grains and legumes - especially any kind of beans (the lignans in the hulls are especially good for treating constipation.) Ground flax seed is also a good choice - very high in lignans, plus lots of phytochemicals that fight cancer. Mix it up with apple sauce. Oat meal is a great choice.
Grapes, eaten with the skins and seeds are actually very good for getting the bowels to move, and they are cancer fighters also. (red, black or purple grapes, or purple grape juice) Apples, eaten with the skin (and you can eat the core, including the seeds - everything except the stem) are an excellent choice. Apple cider works extremely well - the dark, thicker kind, rather than pasteurized cider that looks like apple juice. Although apple juice is a good choice if you can't get cider (kind of the wrong time of year for cider.)
You might also try drinking a cup of moderately hot water in the morning when you first get up. Helps to hydrate - warm and hot fluids are absorbed more quickly into the intestine than are cold fluids - and the heat will stimulate the normal motion of the bowel. Hot tea and coffee can also be used - I recommend green tea, unless you are on a blood thinner.
There is always the good old standby - prunes.
Any of these remedies will provide benefit nutritionally while you are on chemo, as well as hopefully getting things moving along while still being fairly gently on the stomach and bowel.
Sincerely,
Tre