What's the fix for severe constipation?

Medication and diet. Severe constipation can be treated effectively with medications but also it is important to make sure there is no underlying condition presenting as constipation e.G of condition : thyroid disease, irritable bowel, celiac disease. There are both over the counter medications and prescribed medications that can help relieve symptoms.
Colon Cancer. First rule out colon cancer. In children, hirschsprung disease is a consideration. Improve diet, more fiber and more fluids. Some drugs cause constipation. Alcohol dehydrates the git and produced constipation.