There's no hard and fast rule that its stress induced or inherited. If you have UC it does increase chances of the future generations of having it but still that too is highly speculative. I had a weak colon at birth and chronic uncurable diarroeha for the first 2 yrs of my birth. I was only fed on powdered milk and nothing else. It somehow "cured" at that time but trigered back in my teenage.I took alot if stress in my school days with studies and relations.But I've seen many people take far more than I have so I think that the body acts in weird ways to express itself. UC / Chrons I dont really see any difference. Now I try to be very cautious not stressing myself too much. Taking one day at a time. I meditate for 15 mins first thing in morn. followed by 20-30 minutes of yoga and 1 full session of workout in evening. I workout 6x a week and on sundays I find every reason to go out for trekking/cycling. This may seem too much but its a way for me to de-stress all the work load, manage all the hard feelings and as a bonus my physique looks better boosting my overall confidence.
Too much slumber is also not good for your health. Many people tell that don't think about negative thoughts but once you just sit all day doing nothing your thoughts will be more poisonous than ever. I believe a balanced life helps in keeping many diseases at bay.