I'm taking 1 omeprazole 40 mg 1x day, 1 famotidine 20 mg every 8 hours and 1 sucralfate 1gm 3 x day. Can that cause kidney pain?
Unlikely. Sounds like you taking medications that target you stomach - they should not cause any damage to kidneys. Having said that, the visceral (from internal organs) pain and discomfort is often hard to localize due to referred sensation and the way our nervous system works. The best would be to get in touch with your doctor so you it can be examined and discussed in details. .
Multiple drugs. Speak to your physician (P) and ask the P why you are on both Famotidine (F) and omerprazole (O). There is no reason why you should be on both. If any course of action is advised, you should ask your P to stop the F. If you have severe GERD, bid O should suffice. Your kidney pain is not well described, so an answer cannot be given. Speak to your P and get the P's opinion as your P knows you best.