My wife is suffering from lower abdominal pain and she is bleeding on occasion, what could cause that? her doctor told her it might be fibroids.

Lots of things!: Her symptoms are non-specific, but concerning. Gi-related problems can originate from the small intestine (crohn's, infection, partial obstruction), the colon (colitis, appendicitis, tb, altered motility), the kidney & collecting system (ascending infection, stones), ovaries, tubes, uterus, hernias that may contain bowel, bleeding, abscess...You get the point. Have her seek evaluation/treatment.

Fibroids: Uterine fibroids manifest as vaginal bleeding, not abdominal bleeding (rectal bleeding). Please revisit with your doctor.