The first attack I had we called the ambulance. They only took 10 minutes to arrive, but in that time the pain had subsided. I was embarrassed but they insisted I was checked out at hospital. My heart came through with flying colours, but they didn't test further. A month later it all started up with a vengeance and I saw snowdonia from the back window of an ambulance.
I had to go home early and see the GP. I was referred for an ultrasound scan, which confirmed I had gall stones. I had to wait 3 months to a consultant, by which time I had lost a lot of weight and felt generally unwell with lengthening attacks along the way. I was given pessaries to put up my rectum, which took the edge off the pain. Because I didn't have a high temperature etc., I didn't fit the profile for emergency surgery.
Cutting down fat did reduce attacks. The consultant told me that I shouldn't eat more than 2.5g fat per 100g serving. It would have been helpful to know what a low fat diet meant before! So I hope this helps you.
I haven't looked back, once I recuperated from the op and have no problems with healthy amounts of fat. Not sure I could face greasy fish and chips though, but I wouldn't want to anyway.