Hi welcome to the health care magic
According to history it seems to be
acute colitis or dysentery like presentation...
Maintain hydration with lots of water...
Fruits juices will be beneficial...
Take small meal with frequent interval...
Avoid excess spicy foods and fatty meals...
Warm water help in soothing..
You might prescribed broad spectrum antibiotic like
ciprofloxacin plus
metronidazole group..
If no improvement than stool culture done to identify causative organism
As you are having bright red coloured stool, piles should be ruled out by proctoscopy
rectal examination...
Probiotic tablet also prescribed for replenish lost bacterial flora
Take care
Consult physician for examination with keeping my answer in mind
Hope your concern solved