I've had great luck using a "blap" of canned pumpkin with my guys. The extra fiber seems to firm up loose stool and loosen hard. I call it The Great Poop Regulater.
...I guess I should have been more specific, my one boy with IBS does well on the Flint River Ranch Trout and Sweet Potato, it also contains acidophillus and digestive enzymes and is glutten free. If I feed him anything else...oh boy, it is not pleasant.
Any articles you can find on IBS for humans will be helpful in your research.
Had one with that and ended up cooking for her. She would have problems when I tried kibble. Cooked ground chicken leg quarters, rice, veggies etc. She was fine as long as I cooked.
German Shepherds are prone to irritable bowl syndrome. Ask most any GSD breeder and they will tell you beat pulp makes all the difference in the world! If a full medical workup has been done to rule out things such as giardia and other digestive parasites I would recommend trying Royal Canin German Shepherd. It may not be the "natural/herbal" recommendation you were looking for but if it works I would say it's well worth it in the life of a 13 year old dog
I agree with the advice to try the FortiFlora. I have a girl that has been diagnosed with Irritable Bowel Syndrome. She doesn't have diarrhea, but has constipation, burps, has terrible breath, and sometimes must be queasy because she doesn't want to eat. She's had a big work-up with an internal medicine vet and they couldn't really find anything to put their finger on.
Anyway, I have fed probiotics for years, usually Nzymes Bac-Pak or Dogzymes, but this one dog continued to have stomach problems. A vet student friend advised me to use the Forti-Flora instead of my regular probiotics and my sensitive dog hasn't had an issue since. I gave her the course of Forti-Flora in March and so far, so good. This is the first time that this dog has been symptom free in over a year and a half, so I'm a believer.
One of my English Setters had a horrible time with bowel issues until I started giving him Nature's Sunshine Intestinal Soothe & Build. It worked miracles for him and he no longer has any digestive problems.
Diane, Can you be specific? It would be good info to have on hand. There are so many probiotics that don't work, it would be nice to know of one that does.