I’ve had pain and discomfort in my lower abdomen on and off for over 20 years?

I’ve had pain and discomfort in my lower abdomen on and off for over 20 years after straining on the toilet and was diagnosed with IBS. Recently the discomfort has come back and won’t go. Yesterday I had a CT scan and was told there was nothing visible, and that my bloods were all fine but that I’m quite dehydrated. I’m going to ask for a 2nd opinion as I know there’s something amiss…. and my feeling is I may have either and abdominal tear or maybe a Spigelian hernia (I have had 2 bouts of extreme pain and vomiting in the past 10 years). That said in the meantime, is there anything I can buy over the counter to ease the pain and discomfort?… Maybe Laxido or Fybogel?? Many thanks.

Age:41
Male
Medications: None