Hi I can understand your concern....
Here is your approach toward your condition....
First consult surgeon and proctoscopic examination has to be done to reveal if proctitis , fissure , piles etc if present ....
If these cause not there than stool routine microscopic examination done ....
If it shows bacteria and pus cells than bacterial 
dysentery like infection can be there ....And suitable cefixime like antibiotic needed .....
If it shows egg of ameba than 
metronidazole given for 7 days ....
If shows other parasites like hookworm than 
albendazole given ....
Avoid excess spicy foods and drink more water .....
Avoid straining at stool.....
Hope your concern solved ..
And yes if still cause not clear than I suggest you to 
consult gastroenterologist for 
colonoscopy examination and USG ..
Happy to help you further. ..
Take care ...