Looking Beyond the Surface: A Case of Shigella Enterocolitis in a Patient Presenting With Weakness and Substance Use.

Shigella species are common causes of enteric infection, yet atypical presentations can complicate diagnosis in adults. Rising antimicrobial resistance further heightens the need for prompt and accurate identification. Atypical or non-gastrointestinal presentations remain underrecognized and risk diagnostic delay. We describe a 46-year-old man with no medical history who presented with fatigue, abdominal pain, and diarrhea following methamphetamine use. He was febrile and tachycardic with leukocytosis and elevated lactate. CT imaging demonstrated acute colitis, and stool cultures confirmed Shigella sonnei. He improved with empiric intravenous piperacillin-tazobactam and was transitioned to oral levofloxacin based on susceptibilities. This case illustrates the diagnostic challenges posed by unreliable histories, substance use, and non-specific presentations. Early imaging and stool diagnostics were key to timely management. As antimicrobial resistance among Shigella species continues to rise, maintaining a broad differential and guiding therapy with culture and susceptibility data remains essential.