Last time I went to Bangalore, the food / water at the company's guest house made me and my housemate sick. Unfortunately, my sickness kicked in about 3 hrs in the air out of Bangalore enroute to Frankfurt. I couldn't hold down anything including water for more than 15 min.
I landed in Frankfurt and walked a long, long way to my gate destined for Dallas. Laying on the floor (the wonderful cool tile floor), I weighed the pros and cons of aborting my flight and finding a hotel. I didn't have the strength, so I laid there on the floor until boarding time. I kept telling myself "this is gonna be the worst flight of your life. Power through it."
Once I was seated, I looked at the unlucky woman next to me and told her my status. Not contagious but sicker than hell. I had my first experience with the inflight barf bag sitting there waiting to take off. Fortunately, I'm a world class sleeper on flights. I doze off and in the sleep of the dead until.... the food carts came out. This thrust me from my sleep. The smell. Holy hell. The smell. I sprinted to the restroom and camped out there. For the remainder of the flight. Wave after wave of sickness. Dehydration. Occasionally, a flight attendant would come by to check on me. I'd contort myself in all sorts of positions in the stall trying to sleep. By the end of the flight, the flight attendants told me I'd get a wheelchair. I didn't have the energy to do anything but nod.
So, there I am sitting in a wheelchair next to an old woman and a teenage girl who apparently had an emotional breakdown during the flight. I was just laughing at the situation. I did learn one thing. If you have to go through customs, do it in a wheelchair. They open up a special line for the invalids. The customs agent doesn't have the heart to give you a hard time.
Have fun on your trip!