Great topic. I hope those who took longer than a couple days comment on it.
I noticed my stomach with ELOO, but two weeks into SLD I added walnut as my evening dose, and had no stomach sensation at all with the walnut. I wasn't noticing the ELOO at that point, but by contrast there was still a little stomach discomfort. The first 4-5 days, it was like false hunger pains; ice chips in water fixed that. The "noticing my stomach" thing never went completely away with ELOO -- until I switched to a new bottle -- and now I can take 2T all at once. So, I'd say the batch can make a difference. I have a sensitive stomach; daily anti-inflammatories wreck a stomach lining. ELOO had been my baking/cooking oil, and I did the gradual start of 1T once a day for two days, then went up to 1T twice a day.
I have been wondering if sugarwater with oil might aid digestion. I tried that a couple times, with a teaspoon sugar, but not enough to know if it made a difference.