Hello Relly, lansoprazole caused the intolerable dryness side-effect for me, so an alternative as JMCG suggests is worth looking into.
Not sure why you've gone for a low carb diet. I have three bananas, six to eight slices of wholewheat bread, two lots of wholewheat cereal and so on, for gastritis. Just in case anything I do that helps me a bit might be of use to you, I'll put the details below. Excuse the long-windedness, but it's all about the possibility of anyone getting some ease from these blasted illnesses. Best wishes.
Several small/medium meals per day (I have seven medium, one every two hours or bit longer), rather than fewer bigger ones, so you don't overfill your stomach. Eat relaxed, chew well. Be sat upright for and after meals, not bent or reclining, so you don't squash your stomach and press its contents upwards.
Fried foods, high-fat foods/meats, dairy, high-salt foods, spicy-hot foods, tomatoes, carbonated drinks, caffeine, alcohol and chocolate can all impact on stomach and reflux troubles for some people, so personal experimentation is key. Minty foods relax the lower oesophageal muscle, as do some of the above foods and drinks, which can let acid up easier, so they are bad. I use a fruity toothpaste, and strawberry gaviscon tablets for the now only occasional acid burn.
Wholewheat bread, cereals, bananas, hardboiled eggs are a few of the foods that suit me, but there are pulses, rice, various beans (not kidney beans apparently) and many other things to try. Chicken is one of the best meats due to its lower fat content, though even that can hit me and is not eaten lately.
Stress, excercise and bending activity that pressure and squeeze the stomach are also to be avoided. Be as calm and stress-free as you can.
Having your last meal a few hours before bed can prevent or lessen reflux at night, but I found that waiting to be too empty caused hunger discomfort, assorted spasms and kept me awake. Because of this I lie down about an hour and a half to two hours after last meal, and this is much better. I lie raised a bit on three pillows, on my right side, which is best for me, but the left side is recommended as best following tests carried out with sufferers. Other people raise the bed-head itself about 6 to 8 inches or use a wedge affair..
Another thing that helps me greatly is to not burp after ten minutes after eating, as this can bring acid up and cause heartburn. I get the swallowed air out gently just after the meal, sittiing a little forward, then don't burp till after the next meal.
Water triggering heartburn is common. It can happen even with non-ill people. I learned that the best way to get my daily requirement is to drink around 130 ml or bit more with each meal, which, in my case, is added to by some sips of a nutrition drink. So generally I don't have to drink between meals,
In tests there was an indication that some people with reflux suffer heartburn through drinking water in several gulps because their lower eosophageal muscle doesn't open and close correctly when doing this with fluid, and so acid can escape upwards. But just adding water to your stomach between meals, when there is still food and fluids in there, will increase its volume and raise it nearer to the top where the muscle is, the pressure of which, if too much water is drunk, can then cause the muscle to open and let stomach fluid up. Cold water can also cause spasms, so sips of usual water is best.
Some say to drink water only between meals at points when the stomach is empty, but that cannot always be done easily - certainly not in my case where I need to eat every couple of hours or will lose more weight. I can't have between-meal water slowing things down. So I find that a little drink of water with each bite of food that gets well chewed, then a few more af the end of the meal does the trick. I also have water with two cereal meals, which may sound utterly bland but is fine to me, as I avoid dairy milk and have yet to try my cereals with the likes of oat, rice, almond or soya milk. But they are good milk substitutes for people who don't/can't have dairy, unless a person has issues with them.