Foodies Help Required - Tony Soprano Like Illness - What caused it?

I love Indian food and eat it at least weekly either as a take-away or in a restaurant and have only once before suffered any "reaction" or complaint that could not be attributed to the quantity of Cobra or Kingfisher lager consumed.

Recently I went for a meeting & meal with two visiting colleagues at a reasonably upmarket "Bengali" eatery and, as I was driving, only drank two shandies. During the night I was violently ill with two orifices being in demand.

For the record my menu choice was:- Poppadums, then green-lipped mussells in chilli and garlic sauce followed by lamb rogon josh and mushroom pilau rice. All of these foodstuffs have featured in my diet many times but maybe not in this combination before.

I seem to recall a Sopranos episode where Tony suffered a similar experience and it was put down to his choice of seafood and the fact that some of his meal (he visited two different restaurants) was cooked in clarified butter (ghee?).

I have no known food allergies and am used to eating far spicier foods.

The only other time I was ill in this way was 12 months ago after visiting the same restaurant which has been going for years and does have a good reputation - none of my colleagues have ever suffered in any way.

Is there an ingredient in Bengali cuisine that I am possibly allergic to?

I would tend to rule out the mussells / ghee combo as it is on the restaurant's menu and there would have been other complaints.

Any suggestions would be welcome but I have already heard:-

"Don't go there again"
"Don't eat that again"
"Buy shares in Andrex"

etc etc

Many thanks

Ron