There are many reasons why a person can suffer from diarrhea and it is a common cause of anal leakage. One study found that 19 percent of surveyed women reported an episode of anal leakage. Probiotics may help to reduce anal leakage because they improve both the symptoms of diarrhea and constipation. You are correct that your current symptoms could be due to teh conditions that you have mentioned.
How is anal leakage or leaky anus treated?
And thus help to resolve a leaky anus. The treatments suggested there are also suitable to relieve anal itching.