History of Present Illness (HPI)

The patient is a child who has been experiencing left flank pain for one week, accompanied by upper back pain. The onset of pain coincides with the child getting a new trampoline and increasing their jumping activity. The child denies any symptoms suggestive of a urinary tract infection (UTI), such as dysuria, frequency, or urgency. The patient's last bowel movement (BM) was over three days ago, which is unusual since she reports having daily BMs.

Differential Diagnosis

• Single Most Likely Diagnosis
  • Constipation: The patient's history of decreased bowel movements (last BM over three days ago) and the recent onset of flank and back pain, especially with increased physical activity, suggests constipation as a possible cause. The pain could be referred from the abdominal area to the flank and back.
• Other Likely Diagnoses
  • Musculoskeletal strain: Given the recent increase in trampoline activity, it's plausible that the child has strained muscles in the back or flank area, leading to pain.
  • Functional abdominal pain: This is a common condition in children, characterized by recurrent abdominal pain without an identifiable cause, which could radiate to the flank and back.
• Do Not Miss Diagnoses
  • Kidney stone: Although the child denies symptoms of a UTI, a kidney stone could cause severe flank pain and is a diagnosis that should not be missed due to its potential for serious complications.
  • Pyelonephritis (kidney infection): Despite the lack of typical UTI symptoms, pyelonephritis can present with flank pain and is a serious condition requiring prompt treatment.
  • Appendicitis: Although less common, appendicitis can sometimes present with flank or back pain, especially if the appendix is retrocecal, and is a diagnosis that should not be missed due to its potential for severe complications.
• Rare Diagnoses
  • Pneumonia: In rare cases, pneumonia, especially if it involves the lower lobes of the lungs, can cause referred pain to the flank or back area.
  • Intestinal obstruction: This is a rare condition in children without a history of abdominal surgery, but it could cause severe abdominal pain that radiates to the flank and back, along with changes in bowel habits.