Hope you read Jen's post - lots of important stuff there!
Please get your parents to either read Heather's book or log on here. We'd be glad to answer ANY questions they have and I'm sure it could put their minds at rest. And you Mum could have a look at our recipe board and Index to see we really are quite food orientated!
Why not print out some safe, but high cal recipes and ask your Mum to make them with you (good bonding exercise! ). Heather's Butternut Squash sauce with pasta is actually pretty high cal with the pasta and soy milk. And it's soooo yummy and nice to your tummy! And all the sweet stuff would be good. Anti-Depressant Brownies are awfully high-cal .
You need to keep some soluble fibre in your tummy at all times with IBS really. Tell your parents this. Get them to hassle you to eat a bread roll, bowl of noodles, sandwich, pasta, etc... every 2-3 hours and you'll be eating so many calories. They must realise this! And it'll give them something to do so they feel like they can help!
Hope to hear from your parents! What's your name btw?