When manual disimpaction isn't enough: Case report and review of neostigmine's role in refractory constipation management

Severe refractory constipation can lead to fecal retention requiring hospitalization, nasogastric cleanout, or manual disimpaction, and in some cases, surgery. Neostigmine, a reversible acetylcholinesterase inhibitor, is commonly used for pseudo-obstruction but rarely for refractory constipation. Here, we report a 21-year-old male with chronic constipation and likely undiagnosed autism spectrum disorder hospitalized for severe fecal retention, unresponsive to nasogastric polyethylene glycol. Manual disimpaction removed distal stool but left significant proximal stool burden. A carefully monitored trial of intravenous neostigmine, 4 mg in divided doses, resulted in substantial stool passage without bradycardia or other adverse effects. This case highlights neostigmine as a safe and effective adjunct to manual disimpaction. Its use may improve outcomes and reduce the need for surgical intervention in select patients with complex gastrointestinal motility disorders.