Bed wetting can be a very upsetting side effect of cancer treatment, particularly for older children and teens. It might happen because:

• Some chemotherapy drugs increase thirst and others disrupt normal sleep patterns, both of which make bed wetting more likely.
• Intravenous (IV) fluids at night cause the bladder to fill with urine.
• Anything that disturbs sleep (e.g., steroids, anxiety, nightmares, post-traumatic stress) increases the likelihood of bed wetting.

When the bed wetting is caused by drugs or IV fluids, time will cure the problem. If bed wetting continues beyond an expected length of time, or there is pain involved, you can request a consultation with a urologist to rule out any ailments or damage that might require treatment.

My teenaged son wet the bed whenever he was given antinausea medicine prior to high doses of chemotherapy. He was so embarrassed. He was so groggy that even if he woke up in time, I had to help him out of bed and support him while he stood, half asleep, to use the urinal.

There are also psychological reasons for bed wetting during treatment. The trauma of cancer treatment causes many children to regress to earlier behaviors such as thumb sucking, baby talk, temper tantrums, and bed wetting. Punishment for these behaviors only adds to the child’s distress and rarely solves the problem. Following are parents’ suggestions:

• Adopt an attitude that lets your child know bed wetting is “no big deal.” There should be no shaming or punishment.
• Use disposable, absorbent underwear.
• Change sleeping arrangements.

Prednisone and dexamethasone caused my daughter to have nightmares and frequent bed wetting. I felt if she could sleep through the night, the bed wetting might stop. I told her she could sleep with me during that round of chemo, but when the round of chemo was over she would move back into her own bed. It calmed her to sleep with me. The nightmares and bed wetting decreased, and she moved back into her own bed without complaint when the time came.

• Put down a plastic liner covered by fitted and flat sheets, and then put another plastic liner with a fitted and flat sheet on top. During the night, simply pull off the wet top sheets and plastic and there are fresh and dry sheets below. Or purchase absorbent fitted sheets, which can be washed, are softer than plastic, and don’t make the noise that plastic sheets do.
• Keep a pile of extra-large towels next to the bed. Cover the wet spot with towels and save the bed change for the morning.
• Give the last drink two hours before bedtime so your child can go to the bathroom right before bed.
• If your child is bothered by bed wetting, ask whether he wants you to set the alarm for the middle of the night so he can get up and go to the bathroom.
• Give extra love and reassurance.

When my daughter started bed wetting, I didn’t think it was the drugs. I thought long and hard about any additional worries that she might have, and I realized that because her dad had emotionally withdrawn from her during her illness, she might be worried that I would do the same. So I told her one night, “You know, I just realized that every day I tell you how much I love you. But I’ve never told you that no matter how hard life gets and no matter how mad we get at each other, I will always love you. I love you now as a child, I will love you as a teenager, and I will love you when you are all grown up.” She started to sob and hugged and hugged me. She has never wet the bed again.