Ya if these symptoms have been off and on and are now even worse then a trip to the ER would be a good idea. Crohn's can create a lot of inflammation which alone can make the intestines more narrow yet chronic inflammation can cause scar tissue as well which also narrows the intestines. When that happens food can get stuck and create a blockage which makes everything you try to eat or drink come right back up. If its not treated in time it could perforate the bowels which leads to even more problems (infection which can cause you to go septic, infection in the blood which is life threatening). Encourage him to go to the ER or at least ask if you can call his GI office to see if they have someone on call during after hours and see what they suggest (although they may just say to go to the ER).