Blood In Stool (12yo Female MinPin)

Hello, I have a senior miniature pinscher. I've had her since I was a child and only more recently become taking care of her in adulthood. She was never cared for very well and was obese most of her life (weighing over 25-30 lbs when she's meant to weigh about 10-15), I have gradually worked her down to 13 lbs with regular exercise and preventing her from overfeeding (she loves to eat trash and steal food) I cannot afford to take her to a vet, I could maybe manage the checkup fee but it will be some time before we have a clear day in our schedule to take her in, we cannot afford to miss work. We are coming out of homelessness due to my family, so this is not for lack of trying or care. About a night or so ago, she was puking bright yellow, bile presumably, and was experiencing diarrhea. She gets fed twice a day normally, but I switched to the same total amount of food three times a day because looking into it I found that sometimes dogs will vomit bile if their stomachs have been empty for too long. It was very early morning/late night so I only noticed a bit of blood in her feces a bit later because there were stains on the carpet where I had already cleaned it up. Since then she has had progressively more blood in her stool and I'm very worried she could have possibly eaten something outside that may have punctured her bowls or maybe caused an obstruction. My brother is suggesting she may "just have an ulcer". I'd just like to know what to look out for and what I can do to avoid making it worse, because I may not be able to get her in to a vet. I'm considering starting a GoFundMe to pay for the vet costs but I've already done so before for myself to get out of a bad situation and I feel like I'm really pushing it with.. needing help I guess. I called the vets in the area and the local veterinary school, the vets said they can't give me any information even basic input because she's not their patient, the vet school has a Good Samaritan fund for dogs with already confirmed life threatening conditions if you are eligible, capping at $1000, so that would not help in this situation. Thank you for your time and input, please be kind, I am extremely distraught. I can't lose her like this. IMAGES OF BLOOD AHEAD       More recent From earlier today, when there was less blood

I failed to mention that she does not appear to be in pain. She had stopped vomiting the first night and while her stool is soft, it's not diarrhea anymore. This is an image of some of the vomit.

Hello!  And please rest assured, I hear that you love your dog. Animals with a perforated bowel generally present with other signs.  'Just an ulcer' usually refers to a stomach ulcer (I agree, there would be no 'just' about it), but bleeding into the stomach or above would usually present as brown, digested blood. Red blood probably represents bleeding into the large bowel (or perhaps the end of the small bowel) and can have a huge range of causes including Parvovirus, bleeding lumps (cancerous or not cancerous), clotting disorders, bacterial diarrhoea and so on. Most causes are serious enough to merit an examination and require a level of care that simply cannot be provided by Internet chat.  Your vet will hate this situation as much as you do, and will hopefully do everything they can to point you in the direction of affordable care for your dog.  You say that the local vets is not your vet;. who is your vet?  Can they help? The economics of healthcare, both animal and human is deeply distressing and difficult and not unrelated to the mental health crisis in the veterinary profession.  You are hurting, the vets involved will be hurting but more importantly your dog needs some level of care.  What country are you in? - if the UK, the PDSA or RSPCA can often point you in the correct direction to access it. All I can suggest is to avoid apportioning blame at this point and asking questions of vets and charities locally regarding what you can best do to get the care you need.  Asking vets 'what would you do in my situation, given that I am not a vet?' should give you the best that they know.   Wishing you luck.