Abdominal distension and low back pain may be due to ureteritis, pelvic inflammatory disease, colitis and so on. 1. Ureteritis: Ureteritis is an inflammatory disease caused by pathogenic bacteria invading the mucous membrane of the ureter, which can lead to abdominal distension and pain, lumbar pain, and the patient may also have frequent urination, urinary urgency, urinary pain, fever, chills and other symptoms. 2. Pelvic inflammatory disease: Pelvic inflammatory disease is a series of inflammatory diseases caused by pathogenic bacteria infection of female pelvic reproductive organs, including endometritis, salpingitis, tubo-ovarian abscess and pelvic peritonitis, etc. This disease can lead to abdominal distension, lumbar pain, and the patient may also experience lower abdominal pain, increased vaginal discharge, abnormal vaginal bleeding and other symptoms. 3. Colitis: Colitis is caused by microbial infection, immune imbalance and other factors, the disease can lead to abdominal distension and pain, lumbar pain symptoms, patients may also appear in the anxious and heavy (lower abdominal discomfort, want to defecate, defecation after a feeling of incomplete), diarrhea, mucus, pus and blood stools and other symptoms. In addition to the above diseases, other diseases can also lead to abdominal distension and pain, lumbar pain symptoms, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in time to find out the cause, so as not to delay the condition.