bowel blockage or hiatal hernia?

Hi,
I've been having going problems lately, with very small ribbon sized stools, or watery diarrhea. Tried magnesium citrate and passed one decent (not great) stool, followed by many all water ones. The magnesium may have actually flushed me out, but I haven't been eating much lately, worried I have an intestinal blockage. I am eating maybe half a normal meal a day. I am having nearly constant intestinal movement/cramping/gas symptoms. After a second dose of mag citrate (only 1/3 bottle though), I managed to pass 3-4 small ribbon/shaving consistency stools, and one fairly thick diarrhea stool today.

The biggest symptom/worry though is the upper abdominal pain. I wasn't able to sleep last night due to it.
It is a feeling of heavy outward pressure in the center of the abdomen. Like a gas bubble but stronger, and long standing. It is not painful, per se, but very uncomfortable. It makes itself very obvious when trying to sleep. Occasionally It will turn into heartburn/reflux type pains and I will feel things moving through my intestines. The same general area (center of abdomen, maybe very slightly right, just above sternum) is also tender to the touch. Not painful, but is a feeling similar to touching a partially healed bruise on the arm if i push around the area.

I saw my doctor. She listened to my bowels, said they sounded hyperactive. That it was probably a partial blockage, but since I had no pain bending over or moving around, that it wasn't desperate. She prescribed lactulose(15ml bd), and said it would help break up and dissolve the blockage over time. She never suggested any other cause. After coming home and doing some more symptom searching, I read a suggestion of hiatal hernia. Did some more reading and found that a fairly bad hiatal hernia, or strangulated hernia could cause similar symptoms.

There are not much intestines in this area, and it would be kind of odd for the blockage to be right in the center, don't you think? Then again, hernia pain is said to get worse with bending over.

Sorry for my rambling. I cant sleep, and would really like a second opinion to calm my nerves and racing mind.
Any and all ideas would be appreciated.