If increased straining causes diverticular disease then why don't websites list it as a complication of constipation along with hemorrhoids?

Routinely incomplete: Primary driver diverticuli is constipation, delaying emptying (not straining) & largely subconscious. Straining just another symptom, after the fact & occasional. Many factors involved in constipation including lack of activity, low fiber (soluble fiber binds water slowing colon re-absorption), etc. Docs don't know everything, medical advice usually oversimplified/incomplete, usual human behavior!