Pain, cramps and bloating after lunch

Hi everyone, I've been active here a few years back, but have been feeling mostly better (although I'm back on meds recently). However this time, I'm posting for my mother. She's been having anxiety issues (mostly trouble sleeping) for quite some time, but never treated properly. Around 2 months ago she did a check-up and found out she had passed some "light" embolism, which I think made her worry much more. Now 1 month ago she started having pain in the lower right part of the abdomen which has gotten worse. Ultrasound showed no issue and the doctors she has visited think it's IBS because of her anxiety. However she hasn't done any colonoscopy. Also she started escitalopram around 3 weeks ago, but is still at 10mg (will go 15mg today) and it will take a few more weeks to properly work.

In the morning she's usually OK, but after lunch at around 2-3PM the pain/cramps/bloating starts again and gets worse. She's getting Duspatalin wich is helping relieve the pain, but she's very worried that doesn't have a "cure". I wanted to ask if for people with IBS it's "normal" having this kind of pain only after lunch? Any recommendation would be useful?

Thanks a lot