Weird Symptoms Possible IBD?

I've been suffering with some strange symptoms for four years. I have periods of time where I am severely nauseous-- like can't stand up straight, need to be near the toilet at all times kind of nausea. It's completely debilitating. I also have suffered with extreme constipation issues my whole life, and in the last six months they have gotten increasingly worse. I know these aren't typical IBD symptoms but has anyone had some experience like this? They've ruled out gallbladder, gastroparesis, and an upper endoscopy came up clear...? Any advice is appreciated. Thank you : )