Diarrhea and Constipation at the same time? Overflow diarrhea can happen when hard stool becomes impacted in the colon, and loose liquid stool leaks around the blockage. Many people think they have nonstop diarrhea, when in reality they may be severely constipated underneath. Symptoms can include abdominal pain, bloating, nausea, leakage, and frequent loose stools. This often requires medical evaluation because severe stool buildup may need treatment under supervision. In some cases, people requ