I suffer from short bowel syndrome and have in the past been dehydrated to the point of kidney (renal) shutdown. Here are my remedies:
Only sip fluids. never gulp.
Banana for breakfast.
Learn to recognize dehydration i e dizziness, urine color.
Immodium and Lomotil-I take both 4 times daily.
Prevalite (Questran) taken once per day-usually evening.
Sandostatin shots monthly. Expensive but effective.
For emergencies when nothing else works I take Metronidazole(Flagil) to slow me up. It is non-systemic and gone at the end of the day.
I have had a minor stroke and take a blood thinner (Pradaxa) to help prevent another so I must be caregful to not get really hydrated then dehydrated, allowing the Pradaxa to build up on my system, causing internal bleeding. Be thankful you are not me.
These are all my "BIG GUNS" in controlling diarrhea and you and your Dr. shiould choose from my remedies very carefully.
BTW, I was passing 3-4 liters per day.