I'm sorry this happened to you and I do think there could have been some help forthcoming from SOMEONE.
Our experience this past December: Same thing happened to my DIL at HS, except it came out the other end of my DGD. She went to the nearest restroom, and tried to get the baby cleaned first. Each person in the bathroom grabbed a handful of paper towels and handed them to her as they exited. Very nice response! Then after cleaning up DGD my DIL turned her attentions to herself. She cleaned up as best as possible and went in search of clothes. A CM ran and got her a change of clothes from one of the stores (something we did not expect) and when my DIL offered to pay for them, she was told not to worry about it, it was on Disney. Had she met with the same indifference as the OP, she probably would would have cried, too.
While it is easy to say, jump on the bus and head back to your resort, everyone has to realize it is no fun to walk around with vomit/poop all over you, and in crowds such as we experienced in our last visit, my DIL would not have relished the thought of having to board a bus and ride with others in such close quarters smelling to high heaven.
This is a lovely story (the response....not the initial event!), and I'm so glad that your DIL had this experience - which I would consider truly magical, in that situation!
To those who seemingly would have done something different in my situation, and feel the need to tell me exactly how, I don't feel terribly obligated to justify my feelings on how I was treated or how I should have been, more than I already have. That said, I'm certain some of you didn't actually read the whole thread, because I answered many of your questions ("What were you expecting from them?" and "Why didn't you return to your resort", for example) and concerns already.
However, as an additional example....
And in reality--once you were in the bathroom, I don't know what you expected fellow guests to do if you were not actively having a medical emergency. You said other guests didn't offer to help you? If you were where water, soap, and paper towels were available, what was your expectation of fellow guests? You say you had none but then commented on the customer service. I guess I am confused.
She complained about the inadequate amount if clothing for sale within her budget and even had a complaint about fellow guests in the bathroom.
Lisa, I absolutely was not complaining about my fellow guests in the bathroom. If you go back and read the thread, I was responding to another poster who was questioning my avoiding eye contact with other guests when I got off the ride (because, it's embarassing to get puked on in public). That poster suggested that had I perhaps made eye contact with other guests, they would have been helpful and maybe even "offered to hold the baby". My response to that poster was that there's no way anyone would have - or should have - offered to hold my vomit-covered baby, and as an example of that, I gave the numerous other guests in the bathroom who were aware of the situation. My comment to "customer service" is that it's not the job of the other guests to provide excellent customer service - the Disney company, however, prides and markets itself on excellent customer service at its theme parks, so I would have expected more of that from CMs - NOT from other guests.
I do wonder what prevented her husband from taking the son to clean him up while she cleaned him up on the closest immediately available rest room. Kid may have wanted mommy--but no way would I have been trekking looking for a companion restroom. Closest means to immediately handle the issue is what I would seek. To me, that isn't grumpy--that is logical.
Again, read what was posted. We did this. However (and I didn't make this part clear), the diaper bag was with the stroller outside in the stroller parking of The Land. We had limited resources at that initial bathroom. After we went outside to get the stroller and diaper bag, we asked for a companion restroom so that both of us could handle the situation together AND so that I could strip off my pants and clean them to the best of my ability, something that I'm sure would have gotten plenty of looks in a busy public bathroom.
To those who asked about his sickness (I didn't respond to this one yet), and why I didn't take him out of the parks - he seemed otherwise completely fine and was acting normal. Given that he was eating a lot of weird things on vacation that he doesn't normally eat, I figured it was something he ate.
To the sympathetic posters, thank you for your sincere support and kind responses!
(To the comment about baby wipes....I'd love to know what kind of baby wipes you used. Indeed, I had them. And used them. Lots of them. But my kind of baby wipes do not get vomit stuck in zippers and seams and pockets very well. I apparently have been using the wrong kind of baby wipes all along....)