Dad (58yo) Sent home after extreme right ureteral colic & ascending UTI. Worried about his current treatment and whether to switch hospitals

Information regarding my dad:

- 58 years old caucasian male
- 165cm tall
- weight around 70kg
- primary complaint: extreme right flank pain, ureteral colic, UTI
- pain started about 3 days ago, but gotten worse over the days and yesterday was extreme
- he had problems with his kidneys before, about three years ago, similar situation
- current meds: cotrim forte ratiopharm, buscopan, novaminsulfon (prescr. yesterday)
- regular smoker
- country: Germany

So my dad has been suffering from right flank pain for about the past 3-4 days and it started not that painful, but has gotten worse over the course of the days and yesterday it became an extreme pain. So he had to be picked up by the ambulance and they brought him to the ER, they ran blood tests and did an ultrasound.

His discharge papers list two diagnoses:
- Right-sided ureteral colic
- Ascending urinary tract infection

The doctors sent him home today with a regimen of painkillers, an antispasmodic, and antibiotics. They told him to come back tomorrow morning for a follow-up check.

I am extremely worried and have a few questions for medical professionals here:
- Medication/organ failure risk: given the combination of these medications and the infection/blockage, is there a risk of organ failure (kidneys)? I am very anxious about him being at home right now.

- Adequate testing: They only did blood work and an ultrasound. Is this standard protocol for these diagnoses, or should they have done a CT scan to locate the stone?

- Switching hospitals: The hospital the ambulance took him to has a notoriously bad reputation. In Germany, we have free choice of hospitals. Given his condition, is it safe for us to just drive to a different, better hospital tomorrow morning for his follow-up, or would that disrupt his care too much?

Thanks for everyone taking time to answer some of my questions.