HI Lark,
I blog about the science of adversity as a risk factor for chronic illnesses of all kinds and write about adverse events in babyhood (up to 3rd birthday), multigenerational trauma, and onset triggers among others.
If it's helpful, here are two blog posts that summarize the model I've developed over the past 20 years - it's a trauma and nervous system perspective.
Or feel free to pm me
Veronique
Chronic Illness Trauma Studies