Chrones? Celiac disease?

My boyfriend has been having irregular bowel movements for over a year now. Bloody stool, diarrhea, sometimes constipation. He is constantly hungry, even after eating a full balanced meal. He gains absolutely no weight and has been 147 lbs since he was 16, and is now 20. I am wondering what the problem could be. He recently went to his doctor and she is going to send him for blood tests. I am worried it could be chrones or celiac disease. Are these the most common diseases when it comes to having symptoms such as these? They said it was only a fissure before but all of the other symptoms suggest to me that something else could be the problem.. Anyone have any ideas?

[patient915]

It sounds like he needs a colonoscopy.  Trying to figure out what is most common is hard to do and isn't that helpful.  A colonoscopy tests for crohn's, celiac, IBD, and a ton of other stuff.  What is his height (to see if his weight is healthy)?  In general, I would say that if he isn't losing weight, then that symptom is not worrysome.

[amywamy]

He is 5 foot 8 inches and he has not been losing any weight, yet. Just constantly hungry and does not gain any weight no matter what he eats. He is constantly tired as well, he works graveyards so I think that may be the cause of it but maybe hyperthyroidism could be the cause of the weight stabilization as well as being tired all the time. He is scheduled for blood tests as well as a colonoscopy sometime within the next 2 weeks.

[patient915]

His weight is healthy and yes, thyroid problems can cause these symptoms.  This can be easily tested for in a blood test.

[amywamy]

He went for his blood tests yesterday afternoon so hopefully we will hear back soon. He is going for his colonoscopy later on this summer to make sure there is not something more serious going on.