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