Hi Karen Sue,
I’m sorry you are dealing with side effects to treatment. It is unknown how long the diarrhea will last after triggered by Keytruda. Thankfully, melanoma survivors are now living because of immunotherapy (Yay)! However, the side effects from treatment are challenging. My oncologist is seeing diarrhea as a side effect but no answers as to how long we have to deal with it.
I have dealt with diarrhea and nausea for 7 months triggered by Keytruda (and after my last infusion) and have tried many remedies with did nothing (BRAT diet, carob powder, pectin powder, eliminating coffee, probiotics). Imodium is tricky, because too much gives me constipation. So for now, I eat what I want, generally a plant-based diet which has lots of fiber. A year ago I had a routine colonoscopy which showed a beautiful colon, so my onc did not recommend a colonoscopy for now, as she thought the findings would be inflammation, which she said we already know.
Here is my intuition: Even off Keytruda for 7 months, I feel my body is still in an inflammatory state which I hope means I am still fighting off the cancer. While no cancer is seen on my scans, the body might be fighting on a cellular level, and in fact, it’s documented that immunotherapy keeps working after immunotherapy is finished, but for how long is unknown. Maybe the cancer tries to come back and my T cells remember and activate a defense again.
I do hope our guts settle down, and one day we can report when this side effect disappears.