Just read about it here
en.m.wikipedia.org/wiki/Orlistat
I personally wouldn't touch it with a barge pole. It sounds horrific.
You say you are vegetarian and have ibs. Do you eat a lot of wheat, pasta and grains. Do you eat a lot of dairy and sugar.
If the answer is yes this may be why you have ibs as you may have intolerances to all or some of them.
I met up with a friend recently who has been vegetarian for 20 years and has gone back to eating animal protein. She had lost weight, had a vitality about her she never had before and looked and felt amazing.
I really wouldn't put a drug into my body especially one that did that.
I would have a two egg onion omelette for breakfast
A big veggie soup for lunch.We get aldi fresh veg already prepared soup pack and aldi pease pudding which is just lentils. Boil the veg and then put in blender and add pease pudding. A tasty filling soup in 20 mins
Dinner. If you eat fish. I would have fish, steamed veg and a little sweet potato .
Certainly by cutting out the above you will lose weight and you should heal your gut unless you have intolerances to foods that aren't generally triggers.
Ultraclear sustain is a marvelous powder that heals leaky gut. You might want to look at getting some of that. It's full of vitamins and non allergenic foodstuffs.
I'm going to get some more just to give me a boost.
As for that orlistat . Wouldn't touch it. I wouldn't mess up my body with it.