Nizatidine is not available to treat sigmoiditis. Nizatidine is a medication that inhibits the secretion of stomach acid and is mainly used to treat gastritis, peptic ulcers, and gastroesophageal reflux disease (GERD), as well as to relieve the symptoms of heartburn caused by GERD. There are no experiments that have shown a therapeutic effect on sigmoiditis. Adverse reactions caused by nizatidine are dizziness, headache, abdominal pain, diarrhea, nausea, vomiting, dyspepsia, weakness, chest pain, fever, insomnia, and, rash. Nizatidine is contraindicated in people who are allergic to this product or other histamine Hâ‚‚ receptor antagonists. If sigmoiditis and proctitis occur, you need to go to the hospital immediately.