Neostigmine is a treatment option for colonic pseudoobstruction. However, experience in using neostigmine for this indication in pregnant women is limited. We present a case of a woman with an estimated fetal gestational age of 34 weeks presented with what was believed to be a pseudoobstruction and when conservative management failed, neostigmine was administered with no adverse side effects. Ultimately, the patient was found to have a mechanical obstruction and we discuss the challenges in making this diagnosis in pregnancy. Neostigmine may be a viable alternative to colonoscopy in pregnant women for whom mechanical obstruction is properly excluded.