This prospective study was designed to compare the difference of effects of conventional treatment, medicine intervention, endoscopic therapy, and surgery between colon originated and non-colon originated ALGID in critical patients, in order to alert doctors to differ the treatment of the two ALGID and provide basis for treatment.

Inclusion Criteria:

1. Patients in our ICU aged 18-75 years.
2. Patients with a confirmed diagnosis of ALGID.

Exclusion Criteria:

1. mechanical intestinal obstruction (including tumor, stercoral obstruction etc.)
2. gastrointestinal hemorrhage within 72 hours.
3. history of inflammatory bowel disease (ulcerative colitis or Crohn's disease) or radiation enteritis.
4. pregnancy.
5. contraindications of neostigmine administration.