Instead, use a large jar or a Nalgene, or even a plastic pitcher. You want something with a top that is relatively narrow and ideally something with a lid.
They have actually invented portable bags with sturdy rings that people swear by (I would definitely get some for my car if I had kids or if I were a Lyft/Uber driver).
The general idea is that it's so much better if you can keep your nose out of it and also not worry about splashing or getting your hair in the way.
It's also really convenient to be able to put a lid on it, especially if you're in the car or in a waiting room. (the bags have a way of sort of closing up, which I don't quite understand yet)
On the topic of losing fluids:
Dehydration is a big deal, and is typically a larger threat than the bacterial or viral infection that might be causing the digestive upset.
I’ve found Pedialyte to be the most frequently recommended rehydrator at urgent care, and I’ve recently discovered that in addition to the boxes of powdered mix that are easy to store in case of emergencies, they make popsicles that you can keep on hand and freeze when needed. They’re not as concentrated, so three pops are needed to compete with a regular pack, but the format is sometimes easier to keep down. I also recommend 40,000 volts from trace minerals—very gross on its own, but you can add a dose to your favorite juice or sports drink, which can be good if you are sensitive to particular types of artificial or natural sweeteners. The dextrose in pedialyte is another selling point for me.
I also make bone broth (Instant Pot (for Rice & Bone Broth))
And I use grass fed beef gelatin with juice or electrolyte mixes to make jello to help soothe the intestines. (I sometimes add fizzy water to make it more interesting.)
(Roughly: 2TBS gelatin per 4cups juice—mix the gelatin with 3/4c juice to “bloom” while bringing the rest almost to a boil. Mix until dissolved and refrigerate for 4hrs)
And I’ve recently been introduced to Congee (and related Chinese medicine/energetics) which is soothing and hydrating and easy to make in a big batch.
Chicken noodle soup:
The best gf noodle I’ve found for adding to broth is the jade pearl rice ramen from lotus foods (they sell it in single packs with seasoning, as well as multipacks of just noodles which I make with my bone broth and a generous scoop of organic chicken better than bouillon). As they get more able to handle solid food, I sous vide organic chicken tenders (white meat: 150F for 1-3hrs, dark meat: 170F for 1.5-4hrs) and shred/tear them into small bites and add some sautéed (pretty soft) sliced carrots before serving.
Probiotics
For repopulating your gut biome, I’ve heard really good things about Seed as a general probiotic, and VSL 3 for more intensive use (seems similar to this which is available for same-day delivery via Whole Foods, if time is of the essence).