Pain in lower left abdomen, lower bck, bright urine. history of auto immune diseases, lupus, ra, raynauds, on rituxan (rituximab) .urinalysis no bladder inf. ?

Drug side effect: You may only be constipated. Rituxan (rituximab) is a monoclonal antibody used for the treatment of rheumatoid arthritis (ra). Abdominal pain is a common side-effect of this drug. Bowel obstruction and perforation have been reported much less frequently but can be much more serious. Persistent abdominal pain is a symptom you should report to the physician who prescribed rituxan.