I agree on seeing a doctor. OTOH, when I searched "people who smell like feces," it seems that a lot of people who see doctors don't find a lot of knowledge.
If it's leaky gut, you should be able to google "how to heal leaky gut," and get a lot of results with a lot of common advice.
9 Steps to Perfect Health – #5: Heal Your Gut
15 Tips On How to Heal The Leaky Gut | Cook It Allergy Free