Re: Sweet potato
Food doesn't cause a UC flare and from what you describe isn't a trigger, but some foods have action in the digestive tract regardless and can increase activity.
Orange poo only makes sense since sweet potato is orange. It's high in fibre and water...so if your bm was looser/softer, it would be from the sweet potato.
How much did you eat? Did you have anything else with it?
If you are flaring and have inflammation continuing to higher in the rectum and above, bms will come out faster. The less time in the colon, the less time having water absorbed and the colour changed somewhat darker and browner.
All sounds normal to me for possibly anyone, not just a UCer.
It's all a matter of perspective!