Nausea was a huge problem for me during my menstruating years.

. Along with extremely heavy, painful, lotty periods

Oh you eat well tra72. Try to avoid processed foods - I was oK with those until a 3 years ago when I realised that I was eating far too much! [long storey short]. Probably due to my exercise regime altering

I have had IBS for many years, my symptoms manifest themselves as slow transit

. My bowel feels as though it wants to open but nothing happens

: this can go on for days, very rarely does my bowel feel empty! It's not triggered by anything in particular . Most days I'm successful ....... but when it is troublesome it makes going away from the house for very long quite difficult!
I begin my day with 'Lillyes' muesli [wrong spelling

] with added sunflower seeds and dried bilberries: a dash of milk. Black t, 2 sugars. Lunch is difficult to choose: I have fads. Evening meal will be freshly cooked meat/fish with at least 2 veg. : curry with boiled rice: DH can eat eggs but I am unable to digest them so miss out on lots of protein choices.
I've had to give up baked beans as they make me feel very bloated

.
As long as no one tries to separate me from chocolate they will be fine 
Substance: foods that the body takes a while to process. Micheal Mosley's 'clever guts' book gave me an idea as to how long different foods take to process through the digestive tract. Slow release foods: bananas, good quality muesli or porridge

; [ go steady on adding extra veg. ;-). ]. Don't cut out treats though !