Brief Answer:
Please do urine analysis

Detailed Answer:
Hello and welcome to Ask A Doctor service.

I have reviewed your query and here is my advice.

Most probably the red colour is either due to dehydration, some medicine or maybe some red blood cells hemolysed and their contents get excreted in urine.
Kindly let me know every medicine taken during the infection.
Also a detailed urine analysis is needed just to rule out any kidney problem. Although kidney problem is less likely.

Hope it helps. Let me know if I can assist you further.
Dr Vaishalee

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