Chronic diarrhea (> 4 weeks) requires evaluation, as does a shorter (1 to 3 weeks) bout of diarrhea in immunocompromised patients or those who appear significantly ill.
[msdmanuals.com]
In adults, the most common etiologies were secretory diarrhea (idiopathic, laxative abuse, irritable bowel syndrome, diabetes mellitus, and fecal incontinence), malabsorption
[mdedge.com]
Nocturnal diarrhea refers to diarrhea that happens at night.
[medicalnewstoday.com]