Hitler had all kinds of stomach problems. Chronic flatulence was one of the side effects. You can google to find articles but I first read about it in this book.
https://www.researchgate.net/profile/Antonio_Regalado2/publication/6937830_Scientist's_study_of_brain_genes_sparks_a_backlash_Dr_Lahn_connects_evolution_in_some_groups_to_IQ_debate_on_race_and_DNA_Speculating_is_dangerous/links/542195170cf2a39f4af...