Possible bowel infection...
I have read your medical data and understood your concerns.
Having bad odor from anus could be related to possible intestinal infection:
- intestinal protozoa
- frequent bowel movements (due to bypass surgery
I suggest to:
- keep a good anal hygiene
- do cut/shave the local hair and clean it well with warm water and soap (especially after each bowel movements)
- get your stool examined for ova/parasites
- do the culture of stool for candida and get properly treated
- take simethicone
- take probiotics to optimize bowel flora
Hope it was of help!