My daughter came home with a weird rash vagina?

Okay so I picked my daughter up from her father and noticed she was antsy and wouldn’t pee, I gave her a bath and noticed she had a rash (? I think) it’s pretty bad. I’ve had to give her diaper rash cream when she was a young baby but never had her look anything like she did. This was all within two hours of picking her up and I reached out to her dad to ask wtf happened. She’s not allergic to soaps, clothing materials or any food allergies. She’s fully potty trained and can independently wipe proper although I help her to make sure she’s doing it the right way especially when it comes to poo. I’ve had issues with him sending her to his parents any time he’s supposed to have her. Now here’s my problem… his dad is a fucking loser. The worst of the worst, he’s a drunk, aggressive and creepy. I could tell stories for days… now, I didn’t know he was a drunk right away. I ended up working a pt morning job and came home from work to my daughter eyes rolled back in her high chair, with a fever of 104.7 and unresponsive. I threw her in the bath while I went to grab the thermometer to see her temp and he literally fought me, smashed the thermometer and tried withholding me from taking her to the hospital. My mom showed up within 15 mins of me being home and helped me get her out. Now they didn’t run tests but i swear this man did something to her, my ex stepson who was 11 at the time was crying watching her when I walked in, his dad nowhere to be found and told me grandpa took charlotte to the basement and brought her up like this. She was rushed to 3 hospitals, fever wouldn’t drop. Oxygen low, high heart rate. Why they didn’t run tests is beyond me. So basically I left for work, she was happy and healthy, came home to her eyes rolled back and unresponsive and the following morning after she woke up fine in the hospital as if nothing happened, we were released and I packed my shit (we lived with them at the time) and it evidently destroyed my relationship with her father, I left him cuz he wouldn’t use his head. It wasn’t the only problem with his dad, his dad would corner me in the basement and hit on me, I woke up to him watching me, he’d unplug her monitor in the middle of the night. Just weird shit. She has a digestive problem and is on a high fibre diet, takes laxative daily and overall enjoys eating healthy. His parents do not abide by the doctor’s recommendations for diet and won’t give her the meds to keep her regular. She comes back every. Single. Time constipated… it’s gotten to the point where she ended up in emerg to get a suppository cuz I didn’t have the heart to do it myself… she was that backed up. They don’t give her fluids regularly as she’s come back dehydrated. They’re just shitty grandparents. I absolutely do not trust his dad based off these situations and even aside from that, he’s a complete drunk and super aggressive. Grabs her like a rag doll and screams in her face. I don’t parent that way and nobody treats my child like that. Anyways, her father knows this and lies constantly to me. Idk why he won’t keep her himself he’s not incompetent and when he does have her at his place he’s a reasonable dad. He just makes poor decisions. I’ve decided to keep her home.. her dad can’t explain her vagina and doesn’t care. I’m sick of her suffering his shit descisions.. she doesn’t like going to his parents and wants to see him. I won’t deny him her but I will deny him pawning her off every time. Am I wrong? This is what she came home with, he’s unable to explain it and she told me grandpa hit her. Doesn’t have relevance to the rash but like seriously something is up, either they put her in a pull up and sat her soiled or idk