There are a lot of people with IC who have other problems as well like one is Fibromyalgia/Chronic Fatigue Syndrome and others.  Here is what I have also been diagnosed with IC.  

• Nocturia - Nocturia is a condition in which you wake up during the night because you have to urinate. 
• Urinary Frequency - A person with urinary frequency urinates more often than usual.
• Female Stress Incontinence - is any involuntary leakage of urine. 
• Dyspareunia - is painful sexual intercourse for women. The pain can be in the genital area or deep inside the pelvis. The pain is often described as sharp, burning or similar to menstrual cramps. It can have many causes.
• Myofascial Pain - also known as chronic myofascial pain (CMP), is a syndrome characterized by chronic pain caused by multiple trigger points and fascial constrictions. Among the symptoms are referred pain, limited range of motion, and sleep disturbance.
• Stress/depression.
• Constipation/IBS.

There are diets out there that we have to follow and depending on the person eats, depends on their IC.  I have a list of what is allowable and what is not.
Fruits:
What we can have are Blueberries, melons (except Cantaloupe) and pears.  All other fruit are not allowed.
Vegetables:
Homegrown tomatoes and some vegetables.  Store-bought tomatoes, onions, tofu, soybeans, lima beans and fava beans aren't allowed.
Milk/Dairy:
Milk, American Cheese, cottage cheese, frozen yogurt, and white chocolate.  Yogurt, sour cream, aged cheeses and chocolate aren't allowed.
Carbohydrates/Grains:
Pasta, rice, potatoes and some bread.  Rye and sourdough breads aren't allowed.
Meats/Fish:
Poultry, fish and some meats.  Aged, canned, cured, processed chicken livers, corned beef; and meats that contain nitrates or nitrites.
Nuts:
Almonds, cashews and pine nuts.  Most other nuts aren't allowed.
Beverages:
Bottled or spring water; decaffeinated, acid-free coffee or tea; some herbal teas; flat soda.  Alcoholic beverages, including beer, wine, carbonated drinks; coffee, tea, fruit juices especially citrus and cranberry aren't allowed.
Seasonings:
Garlic and some other seasonings.  Mayonnaise, Miso, soy sauce, salad dressing, vinegar and the most important SPICY FOODS aren't allowed.

These are some of the stuff that I keep an eye on or a I test it out.  There are others out there that can eat all of these and not have a problem, it just all depends on the person and their symptoms.  I can drink a small wine but if I go overboard, you bet your butt I will be out for a week or so.  I remember I drank too much and was pretty much out in pain and in bed for almost 2 weeks.  I also take prelief, colon health and I am on so many medicine I can't keep up.  The one I am trying to stop is Percocet.  So most of the medicine I take (Synthyroid, Percocet, Lunesta and other), I can't drink and then chose not too.  The foods, like I said just depends on the person.  I know for a fact that I can't do spicy, I regret it later.  Onion's don't bother me much but then I don't eat a whole lot of them either.  You just have to try and test what you can handle.

So diet and exercise are very important.  I guess some good exercise's are walking, yoga, low impact aerobic, pilates for IC and Tai Chi (which I love).  Also learning to lower your stress helps.  I am the one that is bad here, to quit smoking is supposed to be the thing for you including with IC.  I am going too, I just have to set a date.  Clothing is also important.  You don't want to wear too tight of jeans that will make you uncomfortable and hurt.  I wear lose clothing.  Also make sure you have bathroom access.  You never know when you have to go.  It can come when you least expect it.