Hi I Have A Red Rash From My Butt Crack

Hi I have a red rash from my butt crack all the way the front. It itches sometimes but there are no bumps. I am experiencing hot flashes which I believe is menopause sine August. I have not had a period in over a year. Today I noticed blood spotting on my panties that looked like period spotting but seemed to be located further back near the anus. (I was walking for excercises so don't know if blood came from further forward.
I have no blood in my stool and no cramping. I do not feel bad, take no medicine.
The rash has been around for several weeks but I thought it was from heat or from lack of hygiene (hiking trip of a week without changing underwear or a shower). Should I be concerned?
Suggestions for treatment?