Autism and vomiting

Autism and vomiting Hi everyone, I am new to this and not sure if I will get any comments. I have 3 year old twin girls both with learning difficulties. They have been diagnosed with global developmental delay, pica and are on the list for being assessed for autism (which is evident in both girls). They are both non verbal and cannot communicate at all. Last Sunday, 7 days ago, we took them both swimming in a normal pool, they are use to a hydro therapy pool at school. My eldest Jessica didn’t like it and got upset and was cold. Her sister Lilly loved it. When we got home she didn’t eat much, and didn’t eat much for a few days. She had a poop and then a couple of farts with poop in. On Tuesday she was sick once and then kinda seemed better. I took her to the hospital as I thought she had a uti as her urine smelt really chemically. We waited for a while and were sent home with laxatives as they believed it was constipation. She was still off her food but we gave her the laxido in her drink on Wednesday. On Thursday she did go 4 time and it was very watery. She still wasn’t eating much so I took her to the doctors where she said she had no idea and to ride it out. On Friday she was sick again but seemed much better and we gave her some toast a little while after and she kept it down. I was still concerned so I took her back up to hospital as I thought it could be a partial bowel obstruction. When we got to hospital, she was acting totally normal. Stimming, laughing, bouncing and so on. We were told it could still be constipation or a number of things. And this could last up to 7-10 days. Yesterday which was Saturday, she was sick twice after eating tiny meals but still hasn’t pooped. She had a little fart and follow through. She was clearly feeling unwell as she didn’t stim or do any of her normal activities. Today being Sunday it’s still much the same, she slept all day and hardly moved this morning we have only given her squash little and often which she has kept down. Tonight she has had 1 piece of dry toast and some raspberries. Her twin is okay, and we are too. She keeps having smelly farts and hasn’t pooped. Because she is non verbal she can’t tell us how she is feeling. I have severe emetophobia and am struggling, any advice would be so helpful