Hello, I have studied your case. There is possibility of irritant lesion involving bowel and lumbar muscle leading to back pain. I will advise you to do Ultrasound abdomen and pelvis ,CT scan abdomen and blood investigation according to clinical examination. Another possibility of renal stones which can be seen on ultrasound or IVP. Antispasmodic may help to relieve pain. Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries. Wishing you good health. Take care.