Lower left abdomen pain

So at the start of November last year I got a bad pain in my lower left abdomen and thought it was muscular as I had just started back working out after a month or so off, it was bad enough to cause me pain where sitting up from lying down was sore and hard to do so thought it was my abs maybe. It’s started to fade and then I worked out again and it came back but just as more of a discomfort, like something was digging into me when I was sitting or if I was lying on my right side it would dig into me.

After a few weeks of wondering what it was I looked to what I was eating which was chicken and rice for lunch and dinner every weekday, this had coconut milk which was heavy enough so I tried cutting it out. Within this time I went to the doctor twice, first time they said it was muscular, second time they prescribed me 8 laxatives a day for 2 weeks to clear my system of any blockages. This helped massively and I couldn’t feel it for a week or two but then Christmas happened and it was pretty much roast dinners for a week maybe more and it came back after the third maybe fourth roast in a row and has been back ever since.

Went to the hospital for an appointment and had to give a stool sample that came back all good, a couple of weeks later I went for a CT scan and just got results saying it came back with no issues.

They said an endoscope is the next step but I don’t know what it is or what could be the issue ? I’ve tried reducing dairy, is there anything else I can do or is this even the right place to post ?

Any advice is greatly appreciated 🙏