NEW DELHI (TIP): Union home minister Rajnath Singh on August 14 underwent tests at the All India Institute of Medical Sciences (AIIMS) where he was admitted with complaints of abdominal pain. Doctors performed colonoscopy on him along with few other tests. Colonoscopy is an endoscopic examination of the large intestine and the distal part of the small bowel. “He underwent colonoscopy test Thursday morning. His condition is perfectly stable. He will be discharged by the afternoon,” said a senior doctor at AIIMS. 63-year-old Singh was admitted on August 13 night with complaints of pain in his lower abdomen, sources close to him had said.