Left shoulder pain after eating or drinking

I could really use some ideas here, my doctors so far have no ideas.

Symptoms over the past few months:
- unintentional/unexplainable weight loss
- pain under left shoulder blade (sometimes worse laying down)
- stool issues (undigested food and light, clay-colored greasy stools that float)
- severe burning pain in back after eating too much fat
- fatigue and malaise that do not ease with rest and sleep
- brusing easily and not healing as quickly
- slightly higher blood sugar than normal despite eating well
- slightly high cholestorol despite eating well
- slightly high bilirubin somtimes

History
I was diagnosed with lynch syndrome so decided to undergo my routine testing. I'd like to note that before any of this I had no pain or digestive issues.
1/17 - Colonoscopy/endoscopy, found gastritis and few ulcers
- Started 40mg pantoprazole 1 a day and 10ml Sucralfate 2x a day that week.
2/1 - I can't stress enough how much that this initial presentation seems to be the beginning of all of this, and may or may not be related to the colonoscopy/endoscopy. I've had theories that this was maybe a reaction to the PPI, and infection/complication from my procedure, or even a covid infection.
- Dull pain under my right rib, increasing with severity throughout the week
- Occasional pain on the left lower quadrant
- End of week, pain in specific points in chest, back and neck, (I can't stress enough how this must have been lymph node pain, but what initial presentation would have lymph nodes all over hurt like this? Would an initial cancer spread into lymph nodes make your body react like this?)
- Angina-like heart pain and pain under right rib occasionally severe
- A few sharp shooting pains up right side and continuing pain in middle left back and under right ribs
- No cough, fever, sniffling
3/1 - Heart pain faded slowly while sometimes wrapping around to back
- Fullness like pain under both ribs sometimes
- Dull pain consistently below left shoulder blade
- Later in month, episodes of sever burning in back after eating high fat foods
- Ultrasound unremarkable
4/5 - ER visit
- Portable ultrasound, CT scan and bloodwork unremarkable
4/25 - MRCP unremarkable
4/29 - HIDA scan - 26% (33% is low range of normal)
5/6 - Follow-up endoscopy showed ulcer healed and stomach acid lowered

Concerns
- Cancer (want to rule out due to Lynch syndrome diagnosis just to be sure), something small that wouldn't show up on CT like neuroendocrine
- Colonoscopy complications - infection/gut biome upset
- Other intenstinal issues/blockages
- Pancreas-related issues: pancreatitis, partial blockage, etc.
- Gallbladder-related issues: gravelley stones or sludge not picked up on scans (The 26 percent definatly falls into biliary dyskinesia territory, but would a malfunctioning GB cause this many issues? It didn't show up inflamed in any of the imaging but I've heard of people getting the surgery and afterwards finding out it was diseased. Would a GB attack make your lymph nodes go crazy though? That seems out of place.

I've been tapering off the PPI and have felt slightly better in some ways, but overall feel very weak, and my stool seems greasy and falls part. Sometimes I've had floating stool, sometimes it's darker, but mostly lighter.

The only bloodwork I did close to the initial presentation was an iron test a week after, which showed transferrin saturation percentage was at 60 (anything over 50 is considered iron overload, so what would that mean??)

I started taking probiotics and I'm getting another ultrasound monday, but I don't know what other tests to really ask for, I'm considering going to Mayo Clinic or Cleveland because if this is something serious but hard to find I feel like the clock has already been ticking for months.

@jrofri So many possible causes, from serious to not serious. Personally, left shoulder pain was something I experienced in hospital after undergoing HIPEC with cytoreductive surgery. In my case it was trapped wind in my stomach.

I hope you get to the bottom of yours and get peace of mind, as well as relief
https://www.bimuno.com/news/gut-health/6-ways-to-ease-painful-trapped-wind/

@trippster. Essentially hot chemo was poured into my abdomen cavity immediately after extensive surgery in my abdomen to remove all visible tumours and diseased tissue. I have a huge scar from my pubic bone up to between my breasts where I was cut open to do the surgery. My body was rocked for a few hours to swish the chemo around. The whole operation took 12 hours in my case. I was very lucky to qualify for it after 6 months of chemo and immunotherapy.
https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/hipec-surgery-what-you-need-to-know