How do you manage severe diarrhea during cancer treatment?

It's encouraging that you reached out to your oncology team right away - that was exactly the right step to take when dealing with severe treatment side effects. Many others in the cancer community have found that working closely with their medical team to adjust medications, manage hydration, and sometimes modify treatment plans can make a significant difference in managing severe diarrhea. Hopefully others here will share their experiences and practical tips that helped them through similar challenges during their treatment journey.

Hi Carmine. I don’t know what chemo treatment you’re taking but I did 6 rounds of TCHP and everyone called the P (perjeta) in the TCHP “poopjeta.” Not fun, not fun at all. I used to hate to eat out or eat at home and then go out or go to any functions that was wrapped around food. I had an extra set of clothes at work and my car. I would tell people that if we’re speaking and I interrupt and say I have to go to the ladies room, I’m sorry but I have to go at that moment. I noticed sugary stuff upset my stomach more than anything, but honestly everything did. I’m not sure if there is any food that you should stay away from. I took Imodium D when I would go out but sometimes that went in the total opposite direction and I would be constipated for a couple of days. Didn’t like that feeling. Would rather deal with the diarrhea. It’s going to be trial and error for you. I don’t know what stage you’re at also with your treatments that maybe the one that causes the diarrhea can be stopped. I wish you the best.

Thank you- I don’t leave my house. Sometimes I am up all night with runs to the bathroom or sometimes all day. I would much have this problem, then nausea and throwing up. I have had two rounds of chemo another one coming up on the 16th. It’s probably the perjeta then that’s causing this. I have a recurrence of breast cancer stage one. Blessings

Sorry to hear this. I did not have it this badly. Chemo affects everyone differently. One thing, you definitely need to stay hydrated. Drink water with electrolytes. I didn’t have the nausea either. The day before and the day of I would have chemo, I would fast and just have green smoothies. That seemed to help some with the other side effects. I used to also get some medicine first before they gave me the chemo that help with nausea. I think it was called adevant. I didn’t experience nausea. Keep a journal of what you eat to see how it affects you. Try the Imodium to see if it will help you.

Carmine I have been on Enhertu and Perjeta and like you I couldn’t leave the house taking up to 8 Imodium a day to at least eat anything. Treatment 2 they took Perjeta away and it helped somewhat. Here is what I discovered, taking Imodium when you wake up take Imodium just before you eat take another Imodium. If you have a loose tool that means watery in the morning when you go to bed that’s the only thing that did it for me to not exceed eight a day. Drink a bunch of water.

I have had water poops for almost a year now. It is embarrassing, inconvenient, tiresome, gross, and I hate it. Nothing has helped me at all. I have tried so much, and nothing helps. Ive been told its one of those cost over benefit situations. Cancer or diarrhea? I am getting discouraged that I will never be able to be well again.

Carmine, Sharlotte and Sarah I’m sorry and I know what you are experiencing. I was diagnosed in Feb 2026 right before my 58th birthday with Triple Positive, Estrogen, Progestogen and HERS2 Positive breast cancer. I went through 6 rounds of chemo which I finished in June and had the explosive diarrhea during that time but not too extreme and Imodium AD handled it. I was scheduled for my breast surgery on July 20th; however, on July 19th I spiked a fever over 102 & 103 with no symptoms. I was told by on-call nurse to go to ER as it was on a Sunday. The diarrhea got worse while I was waiting in ER, it was than when I was taking my 6 rounds of chemo treatments. After waiting in ER over 10 hours they finally got a room available for me. After 4 nites in the hospital with all bloodwork and stool specimens results coming back negative they released me. They got my extreme diarrhea under control with an antidiarrheal while I was in the hospital, when I came home it got bad again. Most days it became 14 bathroom visits in a 24 hour period making it hard for my CBC to increase to a normal level. Due to the HERS2+ part of my cancer I have to continue getting the Phesgo injections part of my treatment for a year after completing the 6 chemo treatments. The Phesgo injection I was supposed to get on 7/31 they wouldn’t give me due to the severe diarrhea. That day they called me in a prescription for Lomotil and Questran antidiarrheal meds in addition to the Imodium I had been taking. It seemed to work for 4 days now today the day before my rescheduled surgery it’s hit bad again. My breast surgery was rescheduled for tomorrow, 8/10 at 12:45pm and I’m worried I will have an accident before or during my surgery as I can’t take meds, eat or drink after mid nite tonight. Even when I don’t eat it hits me so I have to worry any time I have to leave home for appts. I was diagnosed in my 20’s with irritable bowel and I think the chemo and antibiotics have triggered it but it’s frustrating because the doctors act like my case if unusual and rare yet I read stuff all the time about cancer meds and diarrhea. I thought once I completed the 6th round of chemo in June that it would get better and in reality its gotten worse. I was sent for a CT scan and more stool specimens last week and they didn’t show a reason for the extreme diarrhea but did show inflammation in my intestines which I expected. It does make you feel like you are all alone on a deserted island and have no life because you have to stay close to a toilet. If you have questions or want to discuss further please let me know. Prayers for all! Lisa