<s>[INST] My 5 year old, non verbal son had been constipated took him to ER Monday pm. Urine test was negative. He is in complete agony upon any urination. He is holding his urine I am assuming because of pain. There is also a blue swollen vein near his pelvis at the top. He only peed twice today even after lots of fluids and also using miralax for constipation. THoughts, please [/INST] Hi, Thankyou for your questionBrief... It could be because of haemorroidsDetailed answer.... As constipation could be the main cause of hemorrhoids and which is causing pain during defecation and reluctance to urinate. My opinion would be got him checked by general surgeon and discuss further. To prevent from constipation make him eat more raw fruits and vegetables like carrots, cucumber,papaya. Hopefully my answer will be helpful. Chat Doctor.  </s>