Hello @bankmary. MS commonly affects the bladder, and in some, the bowels too. Diet might help a lot, but the best thing to do would be to use the search magnifying box in here. Type in the word and you’ll see there are lots of posts on th same subject. If you want a more scientific explanation, try a site like MS Society. It’s lovely that your asking on behalf of your friend

I have had bladder hesitancy and urgency which are both very annoying. Then I started getting bowel urgency. I would maybe go a day, or two, without a BM and then - wham! I had to go like now! I would race to the toilet and basically expel two days worth. Crazy. Thankfully I was usually towards the constipated end of the spectrum so didn't have any disasters. I had a full week of sessions and discussions on my MS at Mayo Clinic in Rochester MN. I learned that many of my "annoying little things" that happen to me are due to MS. The constipation, the urgency, the hesitancy. Our nerves simply do not pass messages correctly to all these functions in our body. As suggested the MS Society has some space on this topic and links https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Bowel-Problems When I called down to Mayo for my appointment the scheduling nurse was asking about my symptoms, When I said I had a numb thigh at the moment and a lot of foot drop. My LFCN nerve was being impacted or compressed somehow. She said that had happened to her as well and gabapentin helped a lot. I asked my neuro for a prescription for that and initially he said no as it wasn't an "MS drug" and the impacted nerve was not part of the central nervous system so it wasn't MS related. I had two EMGs conducted (the second one he did himself) and he agreed to the Gabapentin. It is for nerve pain so while it isn't an "MS drug" it does help manage MS symptoms. It does help me overall right now and I have actually switched to the extended release version that I just take once at night a couple of hours before bed. I like it better and don't feel like my blood pressure is jumping all over and I feel more stable. Another thing that seems to be a benefit is that I am not as constipated. I find that I typically have one bowel movement during the day and it rarely has that big urgency associated with it. It is a wonderful side benefit that I think comes with this "nerve med". While it isn't an "MS drug" I think it is helping me manage MS symptoms and sometimes that is the best we can do. Good luck.