The region you described can have a huge list of diseases which cause pain, but if we see only the region specific most common would be musculo skeletal pain. A clinical examination would be necessary. Other frequent cause can be a ureteric calculi(urine stone disease). I recomment you to visit a General practitioner who would suggest you to do a Ultra-sonography
abdomen and few other routine tests. keeping in mind your current disease it can be also the cause. Hope you find my advise valuable.Feel free for further questions.