I'm on a combination of lansoprazole, naproxen twice a day and co codamol 4 times a day for hypermobility related pain. it says not to take the naproxen on an empty stomach. what will happen if i do? and how much do i need to eat beforehand?

Possible gastritis.: I would follow your daily diet. Take a cracker prior to your meds. This should help.

Stomach pain: Naproxen is an NSAID (non-steroidal anti-inflammatory drug). Often causes stomach upset/pain. Lansoprazole is a PPI (proton pump inhibitor). Decreases acid secretion into the stomach. Reduces the stomach upset that may be caused by the Naproxen. Don’t know co-codamol (not here in US). Don’t take Naproxen on an empty stomach - it can cause stomach pain and, long term, even an ulcer