Fatal Case of Metformin-Associated Lactic Acidosis Associated With Temporary Ileostomy: A Case Report

Metformin is considered a first choice for oral treatment of patients with type 2 diabetes in the absence of contraindications. Colorectal cancer is the second most frequent cancer among the general population; low anterior resections and temporary diverting ileostomies are commonly performed in this population. As the incidence of type 2 diabetes increases, the use of metformin in patients with both type 2 diabetes and an ileostomy will most likely increase as well.

We present the case of a patient affected by colorectal cancer who developed a severe metformin-associated lactic acidosis (MALA) after creation of a temporary ileostomy to protect a low colorectal anastomosis. High-volume output from his ileostomy led to significant fluid loss and electrolyte imbalance, his condition was complicated by MALA, resulting in death.

The population of ileostomy patients who also have type 2 diabetic and taking metformin is at risk for MALA. High stomal output can lead to dehydration, with a loss of fluids and electrolytes and metformin could aggravate this condition, potentiating the risk of MALA.