<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have an irregular belly button and low back weakness. My infant is also very irritable and has back weakness with elbow cramps or spasms. What could be wrong?  <response>: Based on your symptoms, it is possible that your infant has omphalitis, which is an infection of the umbilical stump. It can cause a variety of symptoms such as abdominal swelling, fever, irritability, and weakness. You should bring your baby to the hospital immediately for diagnosis and treatment. 