Sorry you are experiencing this. If the poo is a greyish or clay colour, greasy cowpat consistency, you must ask for a test for Epi (exocrine pancreatic insufficiency). It is called the Tli test, requiring 12 hours fasting . Also a blood test for B12.
It is a treatable but lifelong condition , which few vets learn about. If the Tli test is below 2.4, it's positive . The gold standard information website / forum is epi4dogs.com . Also information on pancreatitis which can segue into Epi.
My springer nearly died before the correct diagnosis , then lived happily with it for another eight years till her heart failed at 12yrs old. Once the pancreas withers , it cannot be regenerated. But the right enzymes and low fibre food will work.
Feel free to pm me if an Epi test is positive.