stomach cramps and diarrhea at night

Hey everyone, I am new to the board. I thought I'd come here to see if anyone might can help cause I don't know what is going on with my grandmother and not even her dr knows. At around the beginning of December, my grandma began to have cramps at night at around 12am and she would have to run to the bathroom, it was not upset stomach but just a really loose bowle movement, she felt like she wasnt finished but couldn't do anything. Every night it would do this and she didn't know why, she went to her dr and she had an x-ray and her dr said she had symptons of divaticulitis but that wasn't it. She gave grandma medicine but that didn't help. So, she couldn't take the cramps anymore and cause of her going to the bathroom so much, she became extremely dehydrated and went to the hospital. She was there for about 4 or 5 days, she had all kinds of tests, colonoscopy, cat scans, x-rays and drs found nothing wrong with her, no tumors...no blockages, but they did find out that she had scar tissue that blocked some of the colonoscopy which was divaticulotis but said that wasn't causing the cramping and bowel movements. They couldn't do a full colonscopy cause of scar tissue so next day finished the proecedure by doing a barum enema and even the results from that didn't pin point the problem...the dr said he THOUGHT that it might be blood vessel not flowing properly and he put her on some meds and put her on asprin a day and sent her home. She felt fine last week but the cramps started back night before last and today she's gone to the bathroom 7 times and Friday she's going to a specialist and see if she can get a second opinion. I really hope that he can find the problem so she can get the proper treatment. If there is anyone here that may have experienced this or knows someone, please let me know. The family is just confused about this, we don't understand.