Ok in a matter of two yrs I've done blood work for IBDs/Celiac, stool cultures, sigmoidoscopy, colonoscopy/endoscopy, barium swallow, pill cam swallow, breath test for SIBO/Lactose Intolerance/Fructose, heck even Permeability test (thinking it was Candida), all coming back negative. Only thing doctors found were internal hemorrhoids. Had them removed but symptoms still persists (incomplete evacuation, the never ending wiping, constant gas, lack of urge to go). Finally found a topnotch Colorectal surgeon who in a matter of 2 mins was able to diagnose me w/ internal rectal prolapse (internal intussusception). Just needed Dynamic MRI of the Pelvis to confirm it, which it did. I'm almost 100% positive this is what causing the odor, because I had no such odor when back then when I was able to normally go.