Feeling very stressed out lately to the point it feels like depression, watery stool for a week with no accompanied pain. 1) could it be linked? 2) when to see doctor for it?

The brain communicates with the gastrointestinal tract &mental health issues can provoke diarrhea or irritable bowel type symptoms. However before assuming that it's the case with you, it's advisable to have a fresh, warm stool sample, even if it's watery, sent to the lab to be checked for pathogens. Also see a mental health professional to get help for anxiety and/or depression. Discuss with MD