What are the bad effects of constipation?

As few as three bowel movements per week is considered normal. That does not mean that even going once or twice per week is harmful, as long as there is no abdominal discomfort and a person is regularly passing gas. However, new constipation that persists for more than a couple weeks should prompt a call for medical advice. Constipation with abdominal pain, not passing gas or vomiting needs immediate attention because there could be a bowel obstruction.