Glad to hear your mum is improving now the medications are kicking in. Sounds like she had quite a nasty attack. Feeling nauseous first thing is also quite common, but it also one of the side effects of the medication as well. A word of warning - this takes a LONG time to get over - weeks in fact. It's not a case of diving straight back into normal life. I've heard of people coming out, eating a cheeseburger and chips and ending up doubled up again!! Or being told - eat fibre - without being told soluble fibre, not insoluble. A bowl of All Bran is very harsh on the still healing insides, bran flakes are a better bet, or a sprinklable bran supplement.
Your mum will have to follow a mainly liquid diet at first, and low residue solids like mash, steamed fish, grilled chicken, plain white bread, scrambled egg, plain yogurt, home made soups. Eat small meals, well cooked and chew well. Then introduce more soluble fibre. She will also need to get her bowels back into a regular pattern, which the medications and illness will have disrupted. I personally have a daily stool softener prescribed, others also take probiotics to replace the good bacteria destroyed by the medications. It is common to have lingering pain, to feel totally washed out, to feel depressed and to suffer fear and loss of confidence. This is what takes time to get over. But if you read many of the posts on here you will see people do slowly improve, and are surprised at how long it can take.
Your mum needs to know this is a disease for life and needs diet and lifestyle changes to manage it, to avoid future attacks. Sadly doctors know little about this disease and offer little or conflicting advice. It's on this forum, with the people who have learned to live with it, that you will get the most help and advice. Everyone is different and we all have to find our own triggers by trial and error.
The most important thing though, if your mum feels it is coming back, fluids only for 48 hours. If no improvement or it worsens, back to the doctors - don't ignore it thinking it will clear up. It might be worth asking her just how long she had been feeling ill before she collapsed. It might have been nothing more than a low level niggling pain, where there has been none before (not to be confused with the lingering twinges from healing), but that will be her future indicator. Mine is normally just that - pain later in the day long after I have been to the toilet. (I normally wake up with twinges, which go after my first loo visit).
It's a lot to take on board all at once, but we are all here to help. Best wishes.