constipation back pain? any advice helpful

[thejrock300]

last month i changed my diet to lose a few pounds. im not grossly overweight, 27 yo, 5'11, 212 lbs, but i wanted to get it down a little. after eating healthier for a week i woke up in middle of the night with the worst back pain in my life., lower left side by kidney radiating all over the flank. i couldnt sit for 3 days and the pain is still there (though subsiding).. when i got the back pain i was constipated for 4 days. since then ive had bloating on the left side only, gurgle noise when eating, stomach pains when i eat a large meal, lots of gas (i have gastritis), itchy anus (had this for a while) and softer and slightly thinner stool. i take magnesium citrate doses daily since the constipation, but i still strain to go.

since im young and i already had an endoscopy 3 years ago i dont want a colonoscopy if i dont need one.

any advice would help. my gaestro tested me for celiac but i didnt have that when i had the endoscopy done 3 years ago, so i dont think its that.

can constipation cause awful back pain? what about a pinched nerve in back causing constipation? the symptoms seem to be getting better but im still worried. thanks.

[thejrock300]

no supplements.

[oxer]

Yea I get it recently. Did you use any soplents or medications, they can cause symptoms.