Most people who are infected with Shigella develop diarrhea, fever, and abdominal cramps. Severity of the disease ranges from mild to very severe diarrhea. Diarrhea is bloody 25-50% of the time and most often contains mucus. Rectal spasms are common. The illness starts 12 hours to 6 days, usually 1 to 2 days, after exposure to the bacteria. Dehydration is also a common symptom.