Patient presents with non-anion gap metabolic acidosis, confirmed by arterial blood gas analysis revealing a low pH, low bicarbonate level, and a normal anion gap.  Differential diagnosis includes gastrointestinal bicarbonate loss (e.g., diarrhea, ileostomy output), renal tubular acidosis (RTA), early renal failure, Addison's disease, and administration of chloride-rich fluids.  Patient's history includes [insert relevant patient history such as diarrhea, medication use, or relevant comorbidities].  Physical examination reveals [insert pertinent physical exam findings such as signs of dehydration or altered mental status].  Laboratory data shows serum bicarbonate of [insert value] mEqL, pH of [insert value], pCO2 of [insert value] mmHg, and anion gap of [insert value] mEqL, confirming the diagnosis.  Further evaluation to determine the etiology of the non-anion gap metabolic acidosis will include [insert planned tests such as urine pH, urine anion gap, serum potassium, serum chloride, renal function tests, or adrenal function tests].  Initial management includes [insert initial treatments such as fluid resuscitation with isotonic saline or treatment of underlying conditions like diarrhea].  Treatment plan will be adjusted based on the underlying cause once identified.  ICD-10 code E87.2 is considered.  Continued monitoring of acid-base status and electrolyte levels is essential.