The seven types of stool are:

• Means: Constipation!!!
  
• Type 1: Separate hard lumps, like nuts (hard to pass)
• Type 2: Sausage-shaped, but lumpy

• Means: "Ideal Stools"
  
• Type 3: Like a sausage but with cracks on its surface
• Type 4: Like a sausage or snake, smooth and soft

• Means: Tending towards Diarrhea or cholera
  
• Type 5: Soft blobs with clear cut edges (passed easily)
• Type 6: Fluffy pieces with ragged edges, a mushy stool
• Type 7: Watery, no solid pieces (entirely liquid)

Color and odor variations of feces (from Wikipedia)

Yellow: Can be caused by an infection known as Giardiasis, which derives its name from Giardia, a tiny parasitic organism. If Giardia infects the intestines it can cause severe yellow diarrhea.
This is a dangerous communicable infection and must be reported.

Another cause of yellowing is a condition known as Gilbert's Syndrome. This condition is characterized by jaundice and hyperbilirubinemia. Hyperbilirubinemia occurs when too much bilirubin is present in the circulating blood.

Black: Due to the presence of blood that has been in the intestines long enough to be broken down by digestive enzymes.

This is known as melena, and is typically due to bleeding in the upper digestive tract, such as from a bleeding peptic ulcer.

The same color change (albeit harmless) can be observed after consuming foods that contain substantial proportion of animal bloods, such as Black pudding or Tiết canh.

The black color is caused by oxidation of the iron in the blood's hemoglobin. Black feces can also be caused by a number of medications, such as bismuth subsalicylate, and dietary iron supplements.

Because liquorice is high in iron, this may also cause the feces to become black. Hematochezia is similarly the passage of feces that are bright red due to the presence of undigested blood, either from lower in the digestive tract, or from a more active source in the upper digestive tract.

In children with certain illnesses, feces can be blue or green. Eating green or leafy food can turn feces green. Babies when digesting solid food for the first time also produce feces which tend to be green and of unusual consistency because of the presence of cells discarded during development of the digestive tract. Food with large amounts of food color can cause feces to be colored. An example is FDA Blue #5, which turns feces green when it reacts with bile in the intestine. The effect is considered harmless, and there have been no reports of ill effects. After a barium meal, the subsequent stool should be white. It is quite noticeable that a mostly vegetable diet will produce much less odorous feces than meat diets.

I got black feces and its painful. I suspect i got Peptic ulcer (http://en.wikipedia.org/wiki/Peptic_ulcer#Treatment).

Reading all the symptoms there, i kinda fit. I guess of the problem persist. I shld see a doctor soon AGAIN :(

Til then! take care of your health people! :D