ACE and intestinal obstruction: Univariate logistic regression analysis showed that the two groups of patients had statistically significant differences in glutamic pyruvic transaminase (ALT), blood urea nitrogen (BUN), the use of angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor antagonist (ARB), the use of thiazide diuretics, inability to eat or intestinal obstruction, vomiting, diarrhea, hypokalemia on admission (p < 0.2) (Table 2).