Aloe vera, pure organic (and very expensive) juice did nothing for me; made me extremely nauseated. There are some of us who can't tolerate various natural items, even though they are themselves straight from Earth. The fact that my daughter and I share the same intolerances (aloe vera, echanesia, gluten, St. John's wort, etc.) indicates to me that there may be a genetic component.
My IC is very mild compared to many posting on this thread and I'm very grateful for that. In my case I've found that carbonated beverages and, sadly, coffee can be irritating. I avoid soda ('pop') for the most part, drink coffee sporadically and never strong brew.
I just discovered that apple cider vinegar (w/a small amount of raw, unfiltered locally-produced honey) helps the IC as well as the various aches and pains from my constellation of auto-immune disorders. Mainstream medicine has saved my life a few times now but I don't do well with so many chemicals (medicines) that I just avoid unless life-threatening circumstances require them.
I started using freeze dried aloe vera capsules for my mild IC, which I have had for 10 years now and can't seem to find a remedy :( Anyhow, I took 2 capsules 3x a day and I really didn't see any signs of improvement.
Don't listen to "aloe has no side effects" Not true.
I have tried the Harvest Aloe. Severe gas, gut ache. Not everyone can use it. They give you a sample of 6 pills for free. 1/8 th of one pill gives me severe problems. Can't use. I have a history of IBS. I eat no sugar, gluten, dairy, alcholol due to IBS.
Many people are helped according to their website. Not me.