
Hi Maddog
I'd advise your girl gets a firm diagnosis sooner rather than later - ulcers can be a secondary response to other problems and treating with ant-acids may well only disguise symptoms which would otherwise have led to further investigation. Black stools result from digested blood rather than obviously red blood which is fresh and may be the result of straining alone. Digested blood is generally a more serious symtom.
If she is of a size to have an endoscopy done (some breeds are too big and require open surgery) I'd go with that and have biopsies taken at regular intervals along the digestive system - if it is IBD or something more sinister, the current regime will not make the problem go away
Unfortunately delay could mean a much poorer prognosis even if only a couple of weeks. Fortunately many problems, including IBD, while incurable, can be managed initially with high doses of steroid treatment, equally high ant-acid treatment and dietary changes.
I wish her well and you too.
regards, Teri