He's never going to get an 'interesting' job when he can't be arsed to work all 20-25 days in a month.
Recipe:
1 mug of boiling water
1 lump of ginger, thumped with the back of a knife/the mug before water goes in it/a tin of beans
Mix the two together. Add a squirt of lemon juice and a teaspoon of honey. Drink.
It stops the majority of nausea in its tracks. when it's not made up nausea at any rate
Most nausea/tummy ache that isn't infective, travel sickness/ear related or pregnancy/medication related is caused by;
Low blood sugar from not eating.
Constipation.
Dehydration.
Not blowing the nose.
Indigestion.
The solutions to all of those are obvious - and the ginger tea can help with all of them. If he refuses ginger, mint can help - hot water, mint leaves and honey/lemon. Or just throw a bottle of Gaviscon at him and tell him to jog on.
There is a subset of people (myself included) who also feel dizzy and nauseous if woken from deep sleep. The cure for that is going to bed earlier.
From the times when I had a lot of nausea (mostly medication/methotrexate/etc), I'd suggest his terrible ailment is addressed by;
Cutting back on 'fun' foods to zero - ice cream, beer, crisps, chocolate,, all snacks, no fried foods, limited dairy. Salty foods can help, such as black olives, salami at a pinch - not crisps, though. Or chips. Or burgers.
Lots of fibre and fluid in meals - which means vegetables. Lots and lots of vegetables, plus some grains/pulses, rather than MccyDs. Soup is good, too.
Getting some snack bars in, so when he starts the morning complaining, you chuck him a bar and say 'there you go, eat that on the way and I'll see you tonight'
Or treat it like a hangover headache - bottle of original Lucozade and a bacon roll on the way into work.
Or, like others have said, send him back to Mummy permanently.