Blood in stool for 1 year, new symptoms starting

My wife is 23 years old, and for the past year, probably about 75% of the time she has had bright red blood in her stool. In the past 2 months, it has been getting worse, and she is passing roughly an ounce of blood now. Also, the blood has turned from bright red to more of a burgandy color, and looks more clotted than before, where it was just mixed in the stool.

She has already been to the doctor, and had a colonoscopy and a barium enema, and nothing was found. Hemroids, cancer, IBD, ulcers, and a
number of other possibilities have already been ruled out. She has had no pain or discomfort at all up until these past couple weeks. She has began to feel bloated when she first lays down to go to sleep. About two days ago, she said she was woke up in the night by a really sharp pinch in her upper stomach, and it happened again while she was driving yesterday.

Tonight, she is having very sharp pains off and on in her lower abdomin (she says it feels like she is going to vomit, but doesn't). I did forget to
mention she has a redundant colon, but according to the doctor, was not behind her bleeding. The closest thing I have been able to find to her symptoms, at least those not ruled out, is Diverticular Bleeding, which I am having a hard time finding details about.

Some other things that may or may not be of interest:
- 23 years old
- Female
- 105 lbs
- 5' 8"
- Diet mainly includes vegetables (rarely eats meat)
- No other symptoms than the ones that recently occurred (no headaches, pain, or stomach aches
- We have 1 child
- She is on birth control (Ortho Tri-Cyclen)
- She is having regular menstrual cycles
- She has no shoulder pain (which seems to be a symptom associated with her symptoms for some diagnoses)
- Pretty frequent urination during the night
- Discomfort when having intercourse
*The last two I mentioned seem to fit Interstitial Cystitis, but doesn't seem to be related to her other symptoms.

If anyone has any ideas on what this could be, your information would be very much appreciated. Thanks in advance.