Is the problem due to my gallbladder?

I started having URQ pain 2 months ago. The pain feels like a cramp or dull ache under my right ribs. The pain comes and goes. At its worst, the pain is not severe - just very uncomfortable. The pain sometimes feels like it's wrapping around my right back a little, although I also have a back injury. Recently, I have also started to have pain to the right of my belly button and occasionally a pinching in ULQ under ribs. The pain seems unrelated to eating. I've been having a lot of gurgling after eating (in URQ and midline right above belly button). No blood in stool, no vomiting, no shoulder pain, occasional/rare nausea, occasional/rare mild heartburn. I have been very constipated. I was diagnosed with IBS with constipation 15 years ago, although my IBS has always presented as LRQ pain. I also haven't had many IBS symptoms for years.

Tests that I have had within the last 2 months:
1) Bloodwork - comprehensive metabolic panel, amylase, lipase, and CBC - all normal
2) Abdominal ultrasound - normal
3) HIDA scan with ejection fraction - normal (50%). I had some minor discomfort after the CCK injection. The discomfort felt like some pressure and pinching, but I wouldn't say that it really reproduced my symptoms. I understand that the Cleveland Clinic found that the measured ejection fraction was not as important as the symptom reproduction in predicting which patients would benefit from removal of the gallbladder. Is it normal to feel some discomfort after the CCK injection, or does the fact that I felt any discomfort mean that I'd probably benefit from gallbladder removal? (Infusion was started 80mins after the study began and infused over 30mins).

My questions:
1) What are my most likely diagnoses?
2) What additional tests would you suggest? (Prefer non-invasive)
3) If a CT-scan is suggested, would an MRI (with contrast) be just as good of an option so that I can avoid the radiation? (I have already had a few CT-scans in my life.)

Thank you!

[Christopher R Watters, MD]

I would consider the HIDA negative. MRI is great for evaluating masses in the liver or bile duct issues but CT would have a higher yield as a screening test in abdominal pain. I would think an upper endoscopy would be in order before other tests are done.

[chikabra]

Forgot to add:
I am a 40 year-old female.