Sammi had a terrible time here with the big D when I first brought her home last May. She was on the same food she was on in her foster home, so it wasn't that. Pumpkin didnt help. Nor did the Immodium. Rice helped a bit if I cooked the heck outta it and then puree'd it Bout the same as baby rice cereal, i guess.
Pasta helped (along with boiled chicken or beef) a LOT better for Sammi, but still didnt clear it up. I thought I would be feeding her a bland diet (boiled and pasta/rice soup) forever! (Vet checked everything, incl our tap water)
The tap water was the culprit There was something she wasn't used to, or was different. (Funny, I am the same way when I travel, and it took my MOM figuring it out!)
But once she got used to it, her stools firmed right up. Took a 3 night trip last Spring and sure enough, that night, after drinking the water at the hotel, D. Ran to the store and bought bottled water (the 3 gal jugs they have) and firmed back up by the next night.
Went to a friend's house a few weeks ago and brought water from home (overnight trip) and no D problems at all.
hth and GL!