We had the same issue with our Thorin (MalxGSD) his entire life. It could be food allergies/sensitivities, but in Thorin's case it was Colitis. It wasn't diagnosed until he was 9 yrs old. Once we got the diagnosis and some tips from the vet, he never had an issue with it again. They recommended we give him a probiotic (Forti-Flora here in Canada). Also he was fed morning and night, the had a midday snack and a snack before bed (usually yogurt and a few treats/kibble). The vet said the key was to make sure he never had an "empty" tummy because it gives the stomach acid a chance to do it's thing. I hope you get things figured out!
"Obey my dog!" - Mugatu
"Who can believe that there is no soul behind those luminous eyes!" ~ Theophile Gautier
"Dogs are not our whole life, but they make our lives whole" - Ok... whoever said this has never had a sick or special needs baby. They ARE our whole life!
R.I.P. my sweet, handsome Thorin. You are missed dearly Dec. 25, 1999 - Mar. 4, 2012