Is it ok for my stomach to be like this?

Before I start I should say that my dad has got crohns disease which the doctors thought was IBS when he was younger so I don't know if that would have anything to do with this. Im a 17 year old and about a month ago I had to leave school as I felt really sick, and I started to be sick loads that day. I thought it was perhaps to do with my diet (Im a very small frame but I eat quite a lot) although later on my parents started to feel nauseous so it was most likely a bug. From then on I quitted eating the quick cook pastas (the ones you can add water to) and soups. I then found that the next week I started feeling feverish and getting stomach ache again, but I found a few days later that once I used the toilet (I went normally after those few days) I felt much better and got my appetite back again. I carried on eating more wholemeal stuff like bread and then I got extremely constipated, to the point I had to use laxatives to get rid of it and the aftermath of the laxatives lasted forever and caused the stool to turn a slightly lighter colour and I was going in the morning instead of the night when I usually go. After this I decided I needed a balanced diet and have decided to start eating things like dried fruit, incorporate a little more bread into my diet and the occasional soup. The only thing I was wondering is when I go my stool is normally in about 5 bits (it has been for the past week) its fairly soft as well but now its a much more normal colour. I was just wondering could this be the effect of changing my diet? Sometimes before I go I get slight cramps/bloated feeling. There is no blood etc.. Sorry for the tmi, I was just wondering what could cause me to use the toilet at slightly different times and for it to be a slightly different consistency than normal, this doesn't sound like anything serious does it? Could it perhaps be a sudden allergy I have develeoped after eating a certain type of food? I have also been quite stressed lately as exams are soon and I sometimes almost get that knot in my stomach feeling when this happens. Also I ate chinese last night and now I feel incredibly bloated and windy again!