I have yet to meet a prep that didn’t have me crapping for multiple days, the average tends to be the original day plus 3 to 4 additional. Yay.
I was hospitalized during the radiation plus oral chemo portion of treatment because of extreme diarrhea - to the tune of 2 bags [1 regular, 1 banana] full bore for the first 2 days, 12 liters. It was going out pretty much as fast as it was going in because I had no gut lining left to keep the interstitial fluid in my body, it was pouring out my butt. [sorry] Immodium [8 times the normal OTC dose] plus lomotil [hyperpoo med as we jokingly referred to it, it has atropine in it] does not work on diarrhea like that because it isn’t a matter of slowing the peristalsis long enough to work, there is no gut lining to slurp the liquid out of the poo stream. It took time out of treatment to get enough gut lining restored before finishing the last week of treatment. If I had access to the old school kaopectate - kaolin and pectin - to soak up the excess volume of liquid, it might have worked long enough to get me through the treatment. [and FWIW, I was drinking 4 to 6 liters a day of electrolyte replacement beverage given to me by my radiation oncology team] I was literally within days of organ failure from dehydration. Yes, I can see death by diarrhea. [I had a verified 17 minutes mouth to toilet bowl doctor verified - tracked by undigested watermelon just eaten. Yay.]