10 month old daughter with diharea and vomitting for 7 days ?

I think you might try a different doctor or call an "ask a nurse" program in your area. Anyone who's been vomiting that long, especially at that age, should be a concern. Further, if she is vomiting at night, that presents the danger of her suffocating on her own vomit which is another reason it should be taken seriously. Might be safter to have her sleep in car seat which will at least allow her to be more upright. I know if it were my child, I'd share your concern.

I'm not a pediatrician but the child should be on Pedialyte at least to prevent dehydration from the vomitting and diarrhea/ And yes, I would be concerned. Probably one of those cases where a second opinion(from an M.D.)would be a good idea.

The first thing that comes to mind is Rotavirus. Rotavirus is a genus of double-stranded RNA virus in the family Reoviridae. It is a GI infection that is the leading cause of severe diarrhea among infants and young children. It typically occurs between the ages of 6 months to 2 years. The symptoms you listed are classic Rotavirus symptoms, the only thing that is missing in the symptoms is fever. Did she run a fever in the last 7 days? The mouth sores are like canker sores or internal fever blisters. This lasts about 8-10 days total. This disease can be fatal due to the loss of electrolytes from the dehydration process. This can lead to organ failure. If you are not administering pedialyte begin that now. Do not give her milk as this is an irritant to her GI tract and will only make the problem worse. If she seems lethargic (abnormally drowsy, sluggish, non-responsive) take her to the ER IMMEDIATELY!
I hope she feels better soon. Keep us all posted. Susu

The bumps in her mouth sound like something called herpes..... not sure about the sed bumps on skin though. My oldest daughter and a friend from church has had herpes before with the bumps in the mouth. That could certainly cause vomiting and weight loss. It could cause weight loss because, well, it's in the mouth.... hello it hurts.... makes you not want to eat. That is my thought...... the bumps, just for extra thought could possibly be from the baby vomiting every night for 7 nights, maybe developed something viral along the way.