The science Behind Shocking Stool
There are few things as mysterious as what comes out of our babies. Deciphering diaper contents can feel like trying to assemble an IKEA table with instructions in the wrong language. What does this mean? Am I doing it right? Can someone help me?
After working with hundreds of women navigating infant food allergies while breastfeeding, the one consistency is the inconsistency in infant stool. Here, we have combined current research with our Free to Feed mommies diaper images to help shed a light on allergy and intolerance reactions. Thank you to each of our contributors!
Currently Available Infant Stool Charts
Amsterdam Stool Form (Figure 1) gives us three basic categories: amount, consistency, and color . Here, the amount is based on how much of the diaper surface area is covered, consistency ranges from watery to hard, and six basic colors are described. Unfortunately, this research and subsequent chart does not consider mucus or blood.
Figure 1: Amsterdam Stool Form 
Figure 2: Diapered Infant Stool Scale 
The Diapered Infant Stool Scale (Figure 2) expanded upon these categories to include two more consistency types known as type 4 (mucousy, stringy, more fluid than soft) and type 5A (watery with curds/solids) . Below, we break down each of the standard categories and discuss how food allergies and intolerance plays a role.
Infant stool comes in a variety of colors, most of which should not be of concern. Brown, green, orange, and yellow poops are all normal and do not appear to be related to changes in age (Figure 3) . Color changes may be seen for a variety of reasons and alone should not be a cause of concern. A few caveats to this are white/gray caulk-like poop, green slimy poop, and red/red-ish black blood in poop. White and gray poop should be addressed by a medical professional as it can indicate bile deficiency and/or liver disorders causing undigested food/milk . We will get into the slimy stuff below.
Figure 3: Stool color across age groups 
Figure 4: Varying levels of blood in stool
Any amount of blood should raise questions (Figure 4). Blood may be seen as bright red to very dark red and vary dramatically in volume. The shade of red can tell us more about the possible origin. Bright red blood is “fresh” and likely came from the colon (lower GI tract) or the anus. Commonly, bright red blood can be linked to anal fissures caused by the baby straining to poop . Alternatively, bright red blood may be indicative of a food allergy or intolerance. Dark red blood often originates from higher in the GI tract and can also indicate food-related issues . This can also be found if mom has cracked and bleeding nipples which does not hurt baby but should be addressed with a lactation consultant.
While the mucus categories were much needed additions to the infant stool spectrum, the verdict is still out on how “normal” it is. According to research published in 2018, a majority of infant stool samples collected were either mucousy or watery (Figure 5A&B) . Unfortunately, this study did not consider other food allergy symptoms, maternal diet, or inflammation markers to truly say whether the collected stool was in fact “normal”. The vast amount of collected stool with mucus does tell us that it may be much more common than we originally thought.
Figure 5: Varying levels of mucus and water in stool 
Mucus is generally believed to be linked to infant food intolerance and allergy symptoms (Figure 6). Based on current research, some infant baselines (no reactions) may include small to moderate amounts of mucus. This can be used as an important tool for parents in conjunction with other symptoms such as colic and rash. In other words, monitoring mucus changes as it relates to dietary adjustments while not assuming that your little must get to a point of zero mucus.
Figure 6: Varying amounts of mucus in stool
Figure 7: Varying levels of watery stool
Watery stool is fairly common for breastfed babies as well (Figure 5C&D). The concern here comes from the balance between watery and diarrhea. This can be difficult because some littles will poop with each feed and still be perfectly healthy (Figure 7). Like many things baby-related, you know your situation best. Contact your medical provider if there is a significant increase in watery stools as it can lead to dehydration.
Hard and solid stool, commonly due to constipation, can also be indicative of food intolerance or allergic reactions (Figure 8). It is important to point out that some infants may go extended periods of time without a bowel movement and not be constipated (struggle passing stool). Not having a bowel movement for several days does not necessarily indicate constipation or a reaction .
Figure 8: Hard stool
Figure 9: “Baseline” examples
Soft but spreadable is what many parents think of when they envision the all-elusive baseline poop (Figure 9). Starry eyed, they describe something akin to peanut butter, often with small seeds which is common for breastfed littles. For some this is the norm, but for some babies this can be difficult to achieve.
Combinations of the above scenarios occur often. An unusual color plus consistency and even amount can make any parents head spin (Figure 10). See the above information to help decipher combo diapers.
Figure 10: Stool combination scenarios
Some littles experience what seems like strange black strings in their poop after directly consuming banana. This is perfectly normal and may even remind you of the black pieces you see when you cook banana bread. A variation of this can be red "strings" in the diaper after banana consumption which is a possible reaction to the banana itself (Figure 11).
There are a number of tests which can be performed on infant stool to check for a variety of issues, to include lactoferrin, calprotectin, occult blood, fecal fat test, and various infection analysis . Lactoferrin is a protein released by white blood cells in areas of inflammation. Similarly, calprotectin looks for actual white blood cells in the stool which is also indicative of inflammation. Fecal occult blood test (FOBT) will tell you if there is blood that cannot be seen with the naked eye. The fecal fat stain informs doctors if there is a malabsorption issue based on the amount of fat left in stool. Other various analysis can be completed for parasites, infections, bacteria, and more.
There are other issues which can impact infant stool. Breastfeeding struggles such as oversupply and lip/tongue ties can cause foamy, green, and mucousy stool . Schedule an appointment with an IBCLC (Lactation Consultant) for an assessment of mechanical, supply, and other possible issues. Excessive drool while teething can lead to increased mucus. Vaccines can lead to any number of changes based on your littles initial response to the shot. Additionally, solids introduction can lead to a full rainbow of crazy colors!
Infant stool can be a powerful food intolerance and allergy tool if we do not let it run our lives. If your little has small to moderate amounts of mucus without any other symptoms, that may be your baseline. Many times, mom will contact us after cutting several foods chasing the all-elusive peanut butter consistency & sweet-smelling poop even though their baby is otherwise incredibly happy and thriving. Conversely, if there are other symptoms still present (slow weight gain, blood in stool, rash, colic, reflux, etc.) you are likely still consuming one or more of your baby’s trigger foods. If you are struggling to get to baseline and a happy healthy baby, we offer one on one consults with Dr. Trill to help develop an action plan for your breastfeeding journey. Schedule a consult here today.
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Figure 11: Normal banana stool (top) & abnormal (bottom)